I recently purchased a 94 Z28 with the LT1 with 192xxx miles. Shortly after I got the car it developed a rod knock. I went and purchased a used LT1 out of a 94 caprice wagon with 57xxx miles. I noticed that while I was swapping out the engines, that the engine that was in my car had aluminum heads and the one from the caprice had cast iron heads. My question is would I get a significant power increase if I were to swap the heads and use the aluminum ones? And if so how much power would I be looking at bolting on?

 

power ratings between the two motors is like 10 hp better for the aluminum head motor, Also your going to have a significant weight difference between the two, i would have the aluminum heads freshened up and run them

 

In stock configuration, the cast iron heads actually out-flow the aluminum ones. If I'm not mistaken, the power difference was mostly attributed to the cam. Swapping the aluminum heads onto the iron headed engine probably won't add much power at all..

There are two advantages in aluminum heads. One is, obviously, weight. The second is that aluminum heads coupled with the reverse cooling of the LT1 can pull head away from the chamber, allowing more ignition timing and compression..on pump gas...without detonation. The reverse cooling also helps the iron heads, just not as much.

If you're thinking about putting the aluminum heads on the cast iron headed engine, also think about a camshaft

 

The aluminum head motors came with 91 octane tuning, the iron head motors with 87octane tuning smaller MAF and grandpa quiet. The power difference is in tuning more than anything else.

 

Thanks for the helping me understand the difference between the two sets and their advantages and disadvantages. Yall have been very helpful.