Hey guys, having to re-research my combo after picking up my 78 318 Truck. Instead of building a boosted slant 6, I'm planning on doing an MPFI/Intercooled/Turbo setup on the 318... Looking to make 400 hp to the crank and the truck is going to be a mild daily driver in a 4x4... The engine has 130K on it and has been run on propane since 1980 and has 95% compression across the board... Also thinking about doing a cam swap while I have the heads off but would like to keep the rotating assembly stock.

Instead of adapting a stock RPM Performer intake to MPFI, and fabbing fuel rails and the like, i was curious if I could bolt on the 5.2 Magnum heads/intake/throttle boddy for the 90's and wire everything up to a MegaSquirt controller?

I have a set of 360 heads that are brand new and rebuilt that I could bolt on but am not sure what year they are. I also already have a Edelbrock RPM performer intake and if I do keep stock Iron heads was planning on running a TB adapter with a 5.0 throttle body? Any suggestions on doing this? Thanks.

Michael

 

To convert it to a magnum heads and intake you'll need to get the adapter kit from a mopar dealer. But it should all bolt up and be able to run off of a megasquirt or the stock ecu if you got a crank & cam sensor setup.

 

not sure where you're from but I've got a 60k mi 5.2 magnum (with the carb intake) that I'd sell for $200. You'd just need the stock EFI manifold and rails and stuff, no need to buy the conversion kit.

 

Yeah. you need to get the adapter system. Since the magnum heads oil through the push rods and the LA heads oil through the actual head itself. So you need the hollow pushrods (make sure to get the right ones P5007477) and watch out for clearance between them and the head. you might have to do some drilling. Jeep/AMC style lifters. Correct magnum valve gear, and valve covers. Magnum intake (some people even get the heads drilled to accept LA style intakes) and looks like you'll be good to go (anybody feel free to chime in if i have missed anything)

 

Sweet, thanks for the posts guys... Looks like I can find the intake assembly for around $100 minus the heads here in WA from a JY...
Any idea what kind of injectors the magnums use?

Also, what would a set of 360 heads do to my compression and would this be a plus? The biggest thing is I already have a set of 360 heads with about 500 Miles on them and a RPM Performer intake that I could rework for EFI and use a TB adapter and a Ford 5.0 Throttle body...

I don't think reworking the intake for multiport would be too hard... What would you do if you were in my shoes? 360 heads/intake or 5.2 magnum topend including heads/intake/injectors/throttlebody... Thanks.

Michael

 

I've got a 5.9 magnum intake just taking up room in my garage. It's been sitting in the junk corner ready to take to the dump for 2 weeks. If you want it, you can have it, just pay shipping, unless you're in the Dallas/Ft. Worth area and want to pick it up.

 

Depends on what you want to do, but why not keep the propane? After working out the exhaust headache, I've been very pleased with my 318 turbocharged on propane in my W200.

 

What 360 heads are they? If they are J's or swirl ports, they are worth selling.

Personally I'd sell off the 360 heads and intake and use the factory EFI stuff. Looks like you're in WA, so my engine doesn't make sense for you, but I'm guessing you could find a complete, running 5.2 magnum for $250-300 with ~100k on the clock.

A 5.2 mag under boost will meet your power goals and you have all factory EFI stuff, rather than having to convert an intake. Seems like the easiest route to me.

 

Hmmm... that might be doable, just a bare intake or does it have any efi stuff?

I want to be able to use MegaSquirt and be able to dial it in... I've already used megasquirt before and I already have some parts/knowledge with a "regular" setup instead of propane... Plus the propane tank in the bed is UGLY lol...

I'm not sure what heads they are, I have to check the casting numbers but they're at home while I'm here at college 75 miles away so I can't check them... I think you're right, if i could find a complete engine for a couple hundred that'd be the easiest thing for me... Thanks for the help guys!

Michael

 

5.2's aren't that expensive. The 5.9's are a lot worse cuz everyone has bought up the cores to make 408's. I think if you search around a bit locally you'll find a good deal. Don't be afraid of one with 100k on it. If you get one, read on here about some of the boost specific issues the truck guys have posted about the magnums.

 

Thanks for the advice man, really helps!

Michael

 

It's the intake, throttle body, injectors, etc. I just removed the whole thing when I started the rebuild. Interested? I've already recieved a couple PMs from guys wanting it, but I offered it to you first, so let me know what you want to do.

 

Also, have you looked into this? I noticed it a while ago while researching my combo. Apparently the stock beer keg intake isn't all that great for performance.

http://www.hughesengines.com/partDetail.asp?partID=12869&eTypeID=10

 

A similar topic came up on the Megasquirt forums recently, and I posted a bunch of info regarding heads and intakes. Some of it might not relate directly to you, but there are some links to some parts that are available.

I think the Magnum heads are worth the swap, but for true performance I'd ditch the beerbarrel unless you're on a tight budget.

A buddy told me there is a year of 360 head that is basically an LA version of the Magnum. Has the swirl ports, etc. Was probably from 91-93-ish, from the year right before the 360 became the 5.9 Mag. For some reason the 360 got updates /changes 1 year after the 318 and 5.2.

360LA heads will drop compression, Magnums will raise it. In a boosted application I think the increased swirl of the Magnums would cancel out any problems that the incresed compression would cause (and throttle response would be better). That's just my guess, though.

http://www.msefi.com/viewtopic.php?p=190220#190220

 

The 302 (318) and 308 (360) swirl ports aren't quite a magnum head, but they were a step in the right direction, something Mopar should have done in the early 80's. Those motors got roller cams too, at least some of them. Those 'tweener' motors get forgotten, but can be made for decent performance as well, especially if you're sticking with a carb (saves the EFI conversion problem) for a driver.

 

Yeah I'm interested... how much would shipping be to Wenatchee WA 98801? Thanks...
Also, that Hughes intake looks awesome but I really don't think it's for me... little to much $$$ lol...

I think the plan right now is to get the truck up and running, and do the magnum head/intake swap and get my Megasquirt running... then hopefully save up some more $$$ and get myself a turbo and fab up my turbo kit and do the install over the period of a weekend... Truck is going to be my daily driver so it can't be down for to long.

Also, isn't there a way to re-drill an LA intake to fit the Magnum heads? Seems that I've seen that somewhere before...

Michael

 

I'll go to the ups store tomorrow and see about what it will take to ship it.

As for a manifold fitting both LA and Magnum heads, here is a performance manifold that will fit both.

http://cgi.ebay.com/ebaymotors/Cros...010QQitemZ200199785291QQrdZ1QQsspagenameZWDVW

 

Sweet! Thanks for the link! Think you can get an idea of shipping here?
http://www.ups.com/content/us/en/shipping/index.html?WT.svl=PriNav

Michael

 

Sweet! Got a lead on a set of '99 360 Magnum Heads for $80 with 100K on them... came off a '99 Dakota RT. Do you think the stock fuel rails and injectors will work with that ebay intake? Should probably email the seller...

Michael

 

moparfreak i would just find a magnum motor thats what i did i had a 340 in my truck and wanted to do the change to magnum heads but while i was thinking about it i hurt my motor and just so happen to come accross a 318 magnum with 70k pulled the heads changed cam springs and put arp studs in,carb intake though and went to a little smaller turbo with it and i love it for the street pulls great on 7#'s for now tunning a bit and then bump it up a few more #'s these magnums run strong for such small cubic inches and its alot to with heads and cam,and on the plus side the magnum motors are hydrualic roller to boot! just my 2 cents good luck.