I have access to some Corvette heads for my 1992 Z28, and was wondering if they are worth the swap. I know they can not hurt, but was curious as to what gain I can expect.

 

Weight savings and you will probably have to reroute your EGR if that bothers you.

 

I was hoping to pick up a few ponies, I am not concerned with the weight savings. I would love a set of AFR heads! I have the vette heads sitting in a shed and was going to use them.

 

They are alumnuim so they will flow better. I would think they would show some gains.

 

Aluminum also sheds heat faster, which makes it less prone to detonation which means you can turn the timing up an extra couple degrees.....I don't know about the runner designs so I can't tell you if you'll gain any power, but I would do a little port work on the Aluminum heads and then stick them on.

 

My thoughts exactly

 

Aluminum makes no difference whatsoever to the flow characteristics of any head. Iron heads can flow the same or better.

Aluminum can save a few pounds and allow for higher compression but that is all. In fact, iron heads, all factors being equal, will produce MORE power than aluminum heads!

So if your 92 Z28 already has an L98 350, the Vette heads will more NO difference in power output. Believe it or not.

 

I have a 1985 L98 vette with cast iron heads and the difference is suppose to be about 5 hp from the heads depending on what year, I think the coolant flow was a little better but other than that people who have changed them have not seen any difference. Aluminum would be better to port but I would go with afr's or something aftermarket for a real power gain.

 

Thanks for the input! I think I will save up for the AFR heads, if I am going to go through the trouble of changing heads I want a big gain.

 

wanna sell them?

 

id imagine that they would give some gains. u can go get a clean up job (porting) on them while they are off and pick up some gains for less than the AFR's.

 

I put the L98 Corvette heads on my engine, and there are three big things you need to watch out for on a 88+ engine. First, the intake bolts are at the 86 and older style, so you will want either an 85-86 TPI intake, or the best choice is an aftermarket intake from Edelbrock or Accel. Second, there is a bolt hole missing for the f-body accessories you will need to carefully drill and tap. Thirdly, those heads dont have the EGR passages, so if you care about that, you will need an aftermarket intake and specially modified headers to route the EGR gasses like the stock Corvettes do.

http://para.noid.org/~thresher/image...1&dispsize=800

 

Really? I would think that aluminium would be alot smoother than iron. I mean both when fully ported then I can see that, but in stock form I would think that the aluminum headswouldnt be burred as much as iron.

 

Would I lie to you?

Seriously, it is true. They are both cast using sand. If you see some sort of jagged gnarly hanging out into a runner or something then grind it off. But you really shouldn't find that at all. Sometimes there are imperfections in the water passages but they are quite minor.

And the reason iron heads produce more power than identical aluminum heads is that they retain heat better, and heat equals power. It also equals detonation if it gets too high, so aluminum's high heat dispersal characteristics help combat that with some high compression engines.

 

Im not calling you a liar lol. But then why are aluminium heads so much more expensive?

Its mostly just that Ive been hardocre into sbcs for about 2 years now, and it seems like I would have picked up a major point like that before now.