These are my thoughts on aluminum heads.
1. if you have the money get them!
2. if your putting them on a block without it being zero decked and having flat top pistons dont bother with them, you can run a full point or more in compression with aluminum heads using the same octane gas, so if you dont have it zero decked and flat tops to take advantage of it, its not really worth it, a steel shim gasket can only do soo much, you need a good quench.
3. this one is obvious, the weight savings which is a plus
4. this applies to both iron and aluminum, purchase a bare set, most of the time if your running a bigger cam you will need valve springs to match and assembled pairs(not all!) usually use stock or much less of a spring rate which kills overall performance
5. If your looking at the edelbrock e streets, those are a good looking set of heads, but ive heard mixed reviews about them (about the installed hardware, not the castings), and before i settled on iron vortecs, i had these in my shopping cart, but since everything i said in number 2 applied to me, i decided to pass, and you cant use a steel shim gasket on aluminum, you need a mls (multi layer steel) gasket, so that right there would hurt my compression ratio.
6. the debate of durability, alot have debated that iron was more durable and less prone to cracking, aluminum is fine and very durable, i wouldnt let this be the deciding factor.
7. again if you have the money and the block is all machined and flat tops installed id definitely go aluminum
As with anything, they both have their pros and cons, but it just depends on what your working with.
Last edited by GM B-Body Forum on Mon Nov 03, 2014 9:34 pm; edited 1 time in total
1979 Caprice Sport Coupe, 400hp Vortec 350, Th350, GM 8.5 w/disc brakes, 3.90 gears Detroit Truetrac, 2.5" stainless duals w/ x-pipe, Dynomax race bullets.
1984 Caprice Sedan, 305 motor, 700r4
1978 Caprice Sedan, 305 motor, th350
1993 L99 Caprice, 4.3 v8, 4l60 trans
1972 Ford F-100, 302 windsor, c4 trans
2001 BMW E46 330i, 3.0L