Currently I have an iron head lt1 out of a roadmaster and I was wondering if I purchased the aluminum heads for it if I would get up to the 300 HP that the aluminum headed lt1's get or is there also a cam change between the 2? Which would be better to have when I build up the engine for performance as well? My plan is to rebuild the engine in a few years with forged internals, new cam, ported or new heads, and a twin turbo setup.

 

The aluminum headed ones from the F-bodies like the one I have didn't make 300hp, I think they topped out at about 275-285. The iron heads you have have been said to flow better than the aluminum ones, but someone else may be able to chime in and say more about this.

 

The iron heads did flow better but if you go with a twin turbo, the aluminum heads will dissapate the heat better so you won't be as likely to get localized hot spots (causing pre-ignition/detonation). Just food for thought....

 

From my understanding the iron heads only flow better at lower lift values and about 5 cfm more in stock form at max lift. For a high performance engine though, you'd be better off going with the aluminum ones.