Aluminum is much more expensive than iron.

 

Well I agree with every thing said so far, if it matters. I have used these heads on my 87 Vette. With a ZZ4 short block and an LT4 Hot Cam. Plus many other mods. The point is, they do not produce much gain without being modified. They have quite small valves and ports in their stock config. as they were designed for torque at low rpm. I would save and get better heads.

 

I've ported my vette L98 heads in my 305 camaro. I love em and for the price i really cant beat it. There are cars out there with different displacement running Aluminum L98 heads running 10's. Some are using power adders, some arent. These heads do a good job at flowing especially when ported.

 

I have not run them yet but I'll find out soon. Here is a link and you can see how I modded my headers to keep the EGR. I just found out about the hole you have to drill and tap when I held up my brackets. The crossover tube is aval from GM for like $60.
http://www.hr3rdgen.org/forums/showt...&threadid=1282

 

if your gonna get the vette heads, the more desirable heads are the 113 castings or "D" port exhausts. They have the better ports to begin with before porting.

Also, Sitting Bull is very correct on the iron heads making more power if the two heads are identical ports and chambers. The weight savings on a small block will out weigh the hp difference on a race motor, but not on a street motor...between the two its usally about 1% more HP in favor of an iron head. Yet how often do you find the same port flow numbers between two heads?

 

1986 review of aluminum heads:
Aluminum cylinder heads were delayed half way through the model year due to cracking around the head attachment bosses which caused a redesign. As a result, all 1986 convertibles and late production coupes received the aluminum cylinder heads. The last 8,594 are believed to have received these heads. The aluminum cylinder heads resulted in an increase in horsepower to 235 hp; up 5hp from the previous model year.

This was the only change in heads for the vette until the lt1 came out. Not a big deal if you ask me, iron is stronger for higher compression (I would use iron for lots of nitrous or blower), aluminum is a more expensive material and easier to port; both vette heads don't compare to aftermarket heads with bigger valves to flow more air/exhaust and bigger ports, 3angle valve job, better springs and roller rocker arms, there are many factors besides just the material they are made from. Just my 2 cents.

 

I had Dart 2 Sportman heads on my engine and it ran 13.9 I got a set off LPE D port vette heads and installed them and picked up 1.0 at the track. They are ported and have bowl work. With the right converter and slicks it should run 12.5 on the motor. I just installed a supercharger but have not been back to the track yet.
Later on I am going to get a set of the AFR 210 for the engine. When I do I will post that the LPE Vette head are for sale.
Check out my web page to see the engine and supercharger.
Page 8. Dont forget to vote while there.