I have a GM goodwrench motor in my truck. I'm almost positive that I'm pressurizing the cooling system. It only overheats when in boost. Anyway the question is is it worth it to change heads? I'm pulling the engine down to take a peak at the stock head gaskets. I have a set of alum knock off heads. They need a little work. My machinist told me about $500. The stock heads are one year old. I wonder what power i would gain by running the alum heads? The current setup is twin t3 turbos with an a/w IC. I'm not looking for a ton of power here. I would like to hit 450-500.

 

Do you know what each head flows? A little work is $500? If the aluminum heads flow quit a bit more I would go that route. The factory cast vortec heads are hard to beat even the one's with the single hump. The three triangle's vortec head flows the best from factory. Is your engine a 96 up? If not vortec then go aluminum. The 062's are the factory cast heads you want, the 906's are the single hump but impead flow on the exhaust side unless you port and go with bigger exhaust valve.

 

Chevrolet Performance 10067353 - GM Goodwrench 350ci/260HP Engine & Packages
Above is the engine I bought.
The heads need to be decked $100
They have 2 bent valves. I'm not sure why so I'll replace them all $150.
Disassemble and clean and check. valve job?
The thing that sucks is they were on a 383 that i snapped the crank in. I think they had 25,000 miles since a cmplt rebuild. I'm not sure why the valves are bent. there is not a mark on them. they could of kissed a piston but you would figure there would be evidence.

 

Any other chevy guys out there?

 

What are the aluminum heads? Brand? Size? Brand new Vortecs are the way to go when it comes to Vortecs unless you already have a pair of good castings. I went through half a dozen heads before I found a good pair to go on my truck, then when the boss overheated his boat motor BADLY and cracked both of his, one phone call to Summit Racing had us a brand new pair of 062s, ready to bolt on, in two days, for like $650. Iron heads will make more power than a comparable aluminum head, but the aluminum heads will tolerate more compression/boost on a given octane fuel, and are easier to port/modify.

 

I wouldn't spend any money on the heads you have. When you order the 062's you will have to get a different intake also, you can get the victor jr that go with these heads and change the cam while in there this will get you close to 400hp. Add 10 pounds of boost on 93 pump gas and you should be close to 600hp @ the crank. This will make a very crisp combo. Lock dist. at 32* take out 1 * for each pound of boost and you should be safe and happy. The 062 heads outflow the G.M. bowtie heads up to .500 lift.

 

Yes, 32° max with the Vortecs, , they are a fast-burn chamber,

 

http://www.ebay.com/itm/Sbc-Small-B...ies&hash=item20ea10d7bc&vxp=mtr#ht_1657wt_681

these are basically the same as mine. They are old style. My machinist told me he always dissaembles and decks heads before installing. He said even edelbrocks have issues and for boosted applications its a must. he also is not confident in the valves the cheaper heads have installed. So he thought it would be better to fix mine than buy these. The vortec question was never visited

 

Bueller?
Bueller?


Feris?

 

So what is the question? The aluminum heads may make more power, but I don't know if I'd want to trust them....if you trust your machinist, let him advise you which way to go, based on your specific parts...for myself, I think I'd be looking at Vortecs. Got a set on my .080 over 350 in my S10 and they are great. I have given some thought to doing twins on the truck too....