Hi all. Welcome to my build thread. I will try my best to be pithy but I tend to have diarrhea of the keyboard on car forums. Your feedback and opinions are certainly welcome here.

The subject of my build is a 1973 Cougar XR7 convertible that I've had since I was a teenager. It's been in storage most of the last 15 years while I played with other toys. I am shooting for 500whp on a Mustang dyno with pump gas and through an FMX 3-speed auto (non-locking converter). Since this is probably pushing the limits of the stock heads, block and transmission, I plan to take it slow. I will stop at whatever power level this combo can make on 92 octane and then switch to E85 and/or replace whatever is holding me back. A Baumann controlled built 4R70W will replace the FMX when it grenades. A 9.2" Dart block (if necessary) and CHI heads will eventually make their way into this build when money allows.

The scope of this build is to fuel inject, turbocharge and intercool the original 351C-2v without cutting the chassis and with minimal new holes cut for bolts, tubing and hoses. For this reason, I will not remove the shock towers and add a Mustang II suspension. I want to retain as much of the original character and components as I can in the interest of simplicity, cost-effectiveness (when possible) and project repeatability. I am documenting this for the benefit of others with classic Mustangs/Cougars as much as I am myself.

A few items below are unknown due to my father having a machine shop rebuild the engine when I was in high school. But here is what I think I have so far:

Engine: 1973 351C (original block and heads)

Block: 0.030' mild rebuild in 1994, has approximately 15-20k miles

Crank: Stock, refurbished (other details unknown)

Rods: Stock, refurbished w/ new bolts (other details unknown)

Heads: Stock, cast iron 351C-2v with new valves, guides and stem seals (open chamber, 'small' ports/valves, alleged to have mild porting on exhaust port inner radius)

Pistons: Unknown, assumed to be stock replacement cast aluminum

Compression: Unknown, assumed to be near stock (8.7:1 or so)

Cam: Crower Ultra Beast hydraulic flat-tappet (278/284 total duration, 220/226 duration at 0.50', 0.529/0.540' gross lift, 112º lobe separation angle, 2200-5000 rpm power band, peak at 5500). I think this cam is probably too much for a normally aspirated engine of my compression. I would love feedback on how well you think this will work with a turbo (reversion issues, etc).

Intake: Weiand X-celerator (Part # 7516, single plane, 351c-2v runners, bunged for port fuel injection, 1500-7000 rpm power band)

Exhaust manifolds: Cast iron GM LQ4 (non-EGR, from 2003 Silverado, adapter plates for use with 351c)

Exhaust manifold adapter plates: Custom designed/fabricated 5/8' cold-rolled 1018 steel (351c bolt holes are counter-bored so low head cap screws are slightly recessed, plates bolts to head, manifold bolts to plate)

Exhaust manifold gaskets: SCE Gaskets copper embossed (PN 4119 1.780' LS1 and PN 4052 351C-2v, installed on either side of adapter plate)

Turbocharger: Turbonetics HPC-75 (billet compressor wheel w/ 75mm inducer, ceramic ball bearing/water cooler CHRA, F1-68 turbine wheel, ceramic coated T4 0.96 turbine housing w/ 4' v-band clamp, stole it from eBay)

Wastegate: Tial V60 (60mm, v-band connections)

Intercooler: None purchased yet (plan on 1000-1200hp air-to-water unit from FrozenBoost.com, opinions welcome)

Alernator: Powermaster (140amp, GM 12SI style, wired for 3-wire operation, v-belt pulley, stolen on eBay)

Fuel injection system: Accel DFI Gen 7 (PN 77040, universal V8 kit)

Ignition system: Accel dual-sync distributor with Malory Promaster coil (Accel PN 77204, works with 351C, 351/400M, 429/460, Mallory PN 29440)

Throttle Body: Accufab 4150 4-barrel (1215cfm, progressive linkage)

Fuel Pump System: Aeromotive Phantom Flex (PN 18310, 450LPH, E85 compatible, installs inside stock, non-EFI tank)

Fuel Injectors: Venom (PN HP-655-8, 55lb/hr, low impedance, hope they aren't junk based on reviews I've seen and non-existence of company)

Fuel Line: None purchased yet (plan on -10 AN supply and -8 AN return, need input on what is most cost effective for E85)

Oil Filter Relocator Adapter: Derale spin-on style (PN 15746, dual inlet/outlet, need to add remote filter mount as soon as I verify that this fits, Ford Racing M-6880-A50 does not quite fit do to LQ4 manifold placement)

Hot-side piping: 304 Stainless (I want 321SS for durability, but due to cost, based on the recommendation of a local competition diesel turbo fabricator and against my better judgement, I am going to try 304SS, feedback here is appreciated)

Above are all of the major things that come to mind. I will update this as I think of things I missed or parts that I add to or change from the list.

 

Here are a few pictures of the stuff I have:

Here is my old Cougar droptop:
#ad

It is a 1973 Cougar that has 1971 Cougar front/read bumpers, grill, head light buckets, tail lights and corner lights. I hated the '70s Lincoln look of the '73 Cougars so I did this swap in high school shortly after I got the car.

Here is the hair drier I snagged on eBay:
#ad

I don't think I need the billet wheel or 4" v-band discharge but I have no complaints for the purchase price. Optioned as it is, it retails for around $2,000. I got it for just under half that, unused and in in the original packaging. I spoke with Turbonetics to verify that it wasn't a knock-off due to the missing serial number label. All indicators are that it is the real deal. I've good luck with them on a previous build, so I'm pretty happy with the purchase.

#ad


#ad

 

Here are a few pictures of the adapter plates that I designed and had a near-by waterjet place fabricate:
#ad

It may not look like much but I dusted off my machine design books and did a lot of design calculations (threaded fasteners) and AutoCAD drawings (alignment testing with full scale printouts) to produce what is shown above (weeks worth of work). The plates are 5/8” cold-rolled 1018 steel. The cold rolled variant doesn’t have mill scale issues and require extra machine like A36 hot-rolled would (my first choice due to cost). This ended up making it a little cheaper. Plates install to heads without issue. Manifolds will once I clearance the passenger motor mount a bit. Spark plug access is as good as stock.

Though I wanted ¾” steel to allow more thickness to blend the difference in port shapes (351C is tall oval, LQ4 is "roundish", slight left-right oval), I am certain that it would have made the driver side manifold bang into the freshly rebuilt power steering gear box. 5/8” still adheres to sound machine design for threaded fasteners (overloaded bolts break before threads strip). I plan to torque each set of bolts to factory specs (around 18-20 ft-lb for 8mm LQ4 bolts, around 20-22 ft-lb for 3/8” 351c cap screws) but may have to play with that a bit if leaks develop.

I stumbled across the similarities between the LS-based engines and the 351C after looking for an adapter plate for a 351C on a marine forum. A guy was trying to use water-cooled 351C marine manifolds on his LS1. From there, I found that the bore centerline spacing on both is 4.4” so the port centerlines are dam near the same. After drawing up the header flanges for both and stacking them on top of each other, I decided that the bolt placement, port size/shape/centerline and proven performance and reliability of the LQ4 truck manifold made it the perfect candidate.

I also looked into 351c Aussie manifolds. Coming from right-hand drive cars, they are the right shape to clear the motor mounts but they have a 2-stud ball-socket joint which I didn’t think would seal properly. I think they might also have the same cracking issues that domestic varieties have been known to develop.

351C shorty or block-hugger headers simply do not work flipped around. I also couldn’t find 302/351W ones that would work either (I could cut the flange off and install a 351C flange, if they did). They were either the wrong shape for my car or the wrong alloy/wall thickness for a turbo header.

For a one-off, fabricated manifold setup, I have a total of around $500 in the plates, low head cap screws, LQ4 manifolds and copper gaskets. If this works any anyone else wants to turbo a 351C (all three of us, hahah) or bolt LQ4 manifolds to something else (I can design plates for other applications), I might be able to get this cost down.

If you think I may have missed a better option, please post up.

Driver side plate and LQ4 manifold test fit:
#ad

With the motor shimmed up 1/2", this side clears the factory Saginaw power steering box with around 1/4" to spare (hard to measure exact amount due to location). Since the motor will rock to the passenger side when loaded, I hope this will be enough.

The stock oil filter (FL-1A) is nowhere near close to fitting. I tried a 90 degree Ford Racing adapter (for sale, btw), but even it wouldn't quite clear the inside edge of the LQ4 manifold. I will try it once more with the copper gaskets installed but I still don't think it will fit. LQ4 manifolds hug the block tightly.

After talking with Trans-Dapt and Derale techs, I am going to try a Derale unit that is around 1-1/4" to 1-3/8" high (as measured off the block from the oil filter sealing surface). If this works, I will buy the corresponding filter mount, hose, fittings and find a new home for the oil filter.

The Derale unit also has a second set of inlet and outlet ports. I could block them off or maybe use one of them to supply the turbo. If not, I plan to use an external plug nearby on the block that has full oil pressure or put a Tee fitting in between the oil pressure sending unit and the back of the block to get oil from there. I plan to tap the pan for gravity return.


Passenger side plate and LQ4 manifold test fit:
#ad

This side still has a slight clearance issue in two spots with the stock, 1/2" shimmed motor mount. If you have a hard top, you could probably shim the motor a full inch or more and make the room needed (it sits lower than a convertible in stock form). If hood clearance on my "already-higher-than-a-coupe" engine weren't a concern, I would try that. but since it is, I plan to grind off the bottom manifold heat shield tab and grind down one of the corners of the collector flange to see if that will give me the clearance I need. If not, I will have to hit the front of the motor mount with a flapper wheel until everything fits. Based on how much material I remove, I will either reinforce the stock motor mount, fab a new one or look for an aftermarket one.

Motor mounts are hard to come by for this car because 1973 switched to a captive style motor mount. In addition, convertibles have a frame perch that raises the motor mounts and the engine a bit higher than a hard top so the exhaust pipes will fit closer to the under-body and inside a convertible-specific reinforcement plate. Because of those two things, I would have to switch to hard-top motor mount perches (also called "frame mounts") and possibly non-captive style motor mounts. If I have to, I will. But I want to run with this as far as I can first.


Top view of engine bay so far:
#ad


Shown here is an aluminum fan shroud that is just setting there almost in place. Once I verify that it fits properly (it needs some trimming), I will add it to my build list above. It is the closest thing I’ve found that will fit a stock 1971-73 Mustang/Cougar radiator core, it’s not too thin to support a 16” electric fan and it’s pretty cheap too. The stock fan and shroud took up room that I will need to run plumbing for the turbo.


Here's a shot of the copper embossed exhaust manifold gaskets that just arrived (Photobucket refused to rotate this picture by 90 degrees for some reason):
#ad


The 351C gaskets (oval shape) are sitting up a bit closer to the camera (resting on top of my junk, test fit 351c head) so the ports look a lot larger than the LQ4 gasket ports. They are actually pretty close in size as far as the vertical port measurement is concerned. Everything goes together like this: 351C head|351c gasket|adapter plate w/ 3/8" low head cap screws|LQ4 gasket|LQ4 manifold w/ 8mm bolts. The embossed part near each port is what actually does the sealing. If they end up not sealing well, I will update this thread with whatever gasket works best but a couple reliable sources for turbo advice are why I went this route.

Thanks for reading this far. More to come!

 

Thanks. The paint work was done around 20 years ago by some high school students as part of an auto body class project. It's held up pretty well for amateur work that was never color sanded or clear coated. It needs to be redone for the car to be anything beyond a "10 footer".

I really liked this metallic blue at the time and still do. But I’ve fallen in love with the idea of a triple black convertible. The short answer is, I’m not sure. It will either be repainted this color or transition to black as I start to redo the interior (need carpet, new leather, etc.) and convertible top.

I'm a Ford guy (Cougars, mostly), but I love those 4th gen F-bodies, btw. The first car I bought on my own was a 1998 SS with Hurst 6-speed and chrome ZR-1 wheels (2 years old at the time). The only mod I did was the SLP CAGS bypass but I wanted badly to do an Incon twin turbo kit. I sold the car a couple of years later when I bought my first house.

 

Can you fix the attachments? I'm really curious to see them since I have an M code 71 Mach 1 Mustang...

 

Yes i suggest using photobucket to host the pics its easy

 

Sorry about that, guys. I'm not sure why the first two show without issue. If you click on the hyperlink for the others, does it show anything?

I will try to fix it later on tonight.

I used to have an m-code '71 cougar convertible, btw. I wish my 73 had those big heads.

 

No worries, but no i cant see anything with the two links... No rush im just really liking your idea for a low cost way to make a ls manifold work on another engine!

 

Yea, I didn't see anything either

 

Guys, I am trying to fix my posts but the edit button that was at the bottom right of each post has disappeared. What am I missing here?

 

Previous post has been fixed so this one is redundant.

 

Here's a shot of the manifolds I picked up for $70 from the local LKQ parts place. I'm not an expert on GM LS-based engines but LKQ lists the same manifolds for 4.8/5.3/6.0L trucks. I made sure to get the non-EGR manifolds (they pulled the wrong passenger side manifold twice).

#ad


I'm not sure if all passenger manifolds have the same EGR compatible heat shield but that's what they gave me. I will have to trim them a bit to clear a couple of tight spots, but I plan to use them unless they really look horrible when installed.


Here is a hurdle that I think I have just cleared:
#ad


Shown above is a 351C fuel pump block off plate (Mr. Gasket PN 1517) and a Ford Racing 90 degree oil filter adapter (PN M-6880-A50). The LQ4 manifold hugs the block tight enough that a mechanical fuel pump will not fit with my adapter plates (I don't need it anyway), nor will the stock FL-1A oil fitler. Unfortunately, neither will the Ford Racing oil filter adapter (did I mention that it is for sale? ). The bolt of the adapter sticks out just a hair too much to get the manifold completely bolted down. I am going to try once more with the copper exhaust gaskets installed, but I think it still won't fit.


To address that issue, I spoke with Trans-Dapt who recommended a lower profile unit than they offer from their competitor Derale. Here's a shot of the one that I think will work:
#ad


It is a screw-on style like the Ford Racing unit but this Derale one (PN 15746, $24 from Amazon) only measures a little over 1-1/4" tall from the gasket surface (engine block) to the top. I am going to try it out this weekend. If it fits, I will need to buy hose, a couple of fittings and one of four different options for the oil filter side of this remote mount setup ($22-30).

 

Since I am converting to EFI and hope to make the car as quick as 500whp and drag radials will make a 3,650lb rag top, I had to do a few other things to get the car up to snuff. Some are still ongoing but here are a few that I checked off my list. Speaking of my list, I am detailing everything (part #s, cost, source for parts, important notes, etc) in an Excel spreadsheet. If any future viewers of this thread want a copy, feel free to PM me. It is incomplete as of today, but there is plenty to get you started. Anyway, I digress.

To drive an electric fuel pump (450LPH, in my case), an electric fan (16" SPAL for me), a stand-alone EFI system, wideband, power windows/convertible top and whatever else I think of, the stock 60 amp alternator wasn't going to cut it.

Here is what I had:
#ad


I removed the old alternator, external voltage regulator and wiring harness that connects the two.

Reusing all of the factory brackets/bolts and without cutting any of the car's wiring harness, this Powermaster unit installed quite smoothly:
#ad


It is a Powermaster 140-amp unit (PN 8-67141) that is based on the robust GM 12SI platform. I had to swap the serpentine pulley that shipped with it to my v-belt one and make a new harness to get the proper 3-wire factory operation, but it really wasn't rocket science. The white plug into the back of the alternator can be purchased for a few bucks from any auto parts store (Duralast PN 205). It allowed me to convert the Powermaster alternator from its default 1-wire operation (simpler install, but not without shortcomings) to 3-wire operation that is standard for most modern cars (late 60s and newer).

The white wire is an "excite" wire that turns the alternator on (makes it ready to charge the system) when you key on the car. If your car has an alternator idiot light, this wire connects to that factory wire in the car's harness (Light Green with Red stripe for classic Fords). If the alternator stops charging, this wire is also what triggers that idiot light to illuminate.

If your car has a factory ammeter gauge (working or not), this wire will be wired differently since you more than likely have a gauge rather than an alternator idiot light. The "excite" wire needs to have a power resistor in series with the green-red wire if no idiot light exists since it needs to detect that equivalent resistance. The Powermaster tech told me a 3-5W resistor with 50-150ohms should be enough to work. I found one at Radio Shack (it is a ceramic brick shape, not one of those puny electrics project ones) for a few bucks.

In the picture above, the power resistor is soldered and shrink tubed as best I could. It will go in a nylon wiring harness after I have the turbo mounted and plumbed. I cut the plug off of the old alternator wiring harness and used it to connect back to the factory green-red wire in the car's harness.

The small red wire is the voltage sense wire. It tells the alternator what the voltage is at the point this wire is connected to in the car's electrical system. The battery side of the starter solenoid, or in the case of factory ammeter gauge Ford's (Cougar XR7s, non-base model Mustangs, etc), the main terminal block are the two most common places to attach this wire.

The big red wire (the main alternator charging wire) goes to the battery side of the starter relay, or again, in the case of factory ammeter gauge cars, to the battery cable terminal block.

Mad Enterprises (madelectrical.com) has some excellent literature (some free, some for sale) on this and other electrical upgrades that can be done for old cars (alternator types, alternator wiring differences, head light relays, etc.).

Here's a picture right after I got everything reinstalled:
#ad


That sucker started charging on the first try and got me 20 miles to my current storage facility so I would call it a success. I left a mess of extra wire because I don't know yet how I will route everything for the turbo and wastegate. I plan to install both very near this location (above a clocked-lower alternator, is my current plan).

 

Here is a shot of the intake manifold I plan to use:

#ad


It's a Weiand X-CELerator single plane unit (PN 7516, 2 barrel ports) that I bought from a local dyno shop owner who modified it for port fuel injection on his Aussie-headed De Tomaso Pantera. At the time (10 years ago), no out of the box options existed for the 351C.

Trickflow now has a couple of EFI intakes that have recently come to market for the 351C. They look like they are based on the old Ford 5.0L style. I didn't check hood clearance but they look too tall to work with a factory Mustang/Cougar hood. Please correct me if I am mistaken.

The throttle body is a billet Accufab unit that I purchased used with the intake. I just had it serviced by Accufab since the previous owner had cut off a throttle cable arm that wasn't needed for a rear engine Pantera (probably hit his air cleaner) but is required for my application. Not only did George with Accufab replace the modified arm, he also replaced all moving parts (completely rebuilt it), cleaned it and tested the sensors (TPS and IAQ) for proper operation.

While it was with Accufab, I asked George about a carb hat spacer that they sell for this unit to make the original arm clear low profile air cleaners. Instead of sending me a picture of it with dimensions as I had requested, he sent me the part for free when he returned by refurbished throttle body. All i paid was $35 for shipping (to-from California) for everything. I am not affiliated in any way with Accufab, but I cannot speak highly enough about their customer service. They stand behind their products better than anyone else I've encountered.

On top of the 4150 style 4 barrel throttle body, I plan to use the biggest carb hat that will fit under my hood. Keep in mind that I shimmed up my motor 1/2" and already have the taller Mustang/Cougar convertible motor mount frame perches. Hood clearance is already a bit for me as a result.

 

Here are a couple of shots of the Aeromotive electric fuel pump conversion kit (Phantom Flex PN 18310) that I am going to use:
#ad



#ad



#ad



The Phantom in-tank kits are fairly new products that won a new product award at the 2013 SEMA show. You use your factory fuel tank, emptied and cleaned of vapors. After that, this kit has a template to cut and drill the holes used to drop in and seal the in-tank fuel pump guts. The guts are longer than needed for most applications and need to be measured and cut to the proper depth for your application. The black billet aluminum hat sticks out on the top of your tank and allows for AN supply/return fittings and a roll-over vent valve. The one I bought works with E85 and pumps 450LPH (probably too small for my 670 crank horsepower goal on E85 but it should flow enough for pump gas). They have smaller ones as well as a bigger, dual-pump unit.

I liked this product because it is way cheaper than a custom 71-73 Mustang/Cougar fuel tank that is set up for an electric pump and also because I didn't want to use a fuel cell (I like and use my trunk space). The competitor to this product (a bit cheaper, but not by much) is alleged to have fuel starvation issues under hard corning (not a concern to me) and hard acceleration (this is a deal breaker for me). The baffling of the competitor is way smaller and it lacks the fuel cell foam that the Aeromotive units have to keep gas near the pump .

 

Thanks for getting the pics up i love the inginuity! I will look forward to seeing this come together! Thanks

 

Here's an update on my build.

I got the LQ4 manifolds and adapters to completely fit this weekend!

Not wanting to repeatedly crush and then remove the copper embossed exhaust manifold gaskets that I just purchased, instead I measured the thickness of both sets of gaskets (each head will get one of each style gasket) and then used a couple washers of the correct thickness under my adapter plates to get the manifolds the correct distance from the heads. Once that was done, I dusted off my Dewalt grinder and flapper wheel.

For the passenger side of the car (driver side LQ4 manifold flipped forward), after I cut/ground off the bottom heat shield bolt tab, most of my interference issues went away. I was shocked at how close it was to fitting. For a car with hard top motor mount perches or application with room to spare under the hood, shimming up the motor another 1/2' (for around 1' total) should make it fit with no other modifications. For my convertible/stock hood application, instead of raising the engine higher (which may very well work, I'm just assuming it won't), I decided to grind a little bit of material off the corner of the LQ4 collector flange and a small amount off of the front edge of the motor mount (the engine side of the motor mount). I didn't do a finite element analysis on the modified motor mount (it was 2AM), but engineer's intuition tells me that it was an inconsequential amount.

Removed lower heat shield bolt tab from LQ4 manifold (the OEM driver side manifold used on my car's passenger side)
#ad


Ground a bit off of the front edge of the car's passenger side motor mount (LQ4 driver side manifold, this motor mount grinding might not be needed if the motor is shimmed up more than ½')
#ad


The driver side of the car was a different story. What I thought was going to be a quick job ended up requiring 10-12 test fits to get everything installed. The Derale oil filter adapter installed easily but had the highest portion of its side profile lined up in the worst possible way with the back edge of the manifold.

Top edge of Derale unit hits back of car's driver side manifold (LQ4 passenger side manifold)
#ad


Had the threads that attach it to the ¾' UNF threaded oil filter fitting of the engine block been cut differently so as to clock it a certain way, no grinding of anything would have been required and that would have been it. But, because of the way it was oriented when fully tightened against the block, the top of one of the two sets of oil supply/return ports required extensive grinding to make clearance for the manifold. As it sits, they are still very close to the manifold but not touching.

#ad


#ad


#ad


I think it will work without leaks as is, but to me it looks borderline half-assed. For that reason, I am going to measure how much thread engagement exists between the threaded oil filter boss and the Derale unit. If excess thread length exists, I am going to try to cut down the oil filter boss just enough so the starting thread gets the Derale unit oriented the right way. If excess threads do not exist, I might try to remove the boss and see if I can shim it outward a bit assuming it has some sort of hard stop inside the block to shim against. I've never removed one so I don't know if they have a hard stop or if they are just tapered and stop by virtue of eventual threaded diameter interference.

Does anyone know what stops this oil filter boss from threading into the block further?
#ad

 

are you removing your pics on purpose? All of your pics besides the latest set are gone. :-/

 

I don't know what is going on here. I've been on car forums and used Photobucket to host pictures for 11 or 12 years. I did not delete the pictures. In fact, they showed up as recently as this morning. Until just now, I hadn't been on here or on Photobucket since this morning.

I will reedit my posts when I get a minute. Sorry about that. FAIL.