DIHON

My 67 has a 351W with Holley 750, Torker 2 intake, 280H Comp cam, flat top pistons, 1 5/8 long tube Hooker longtube headers, 2.5" exhaust, C4 tranny with 2800 stall, 4:10 gears, and factory heads. The car runs very well, but I'm wanting to get more out of it, and may eventually go to forced induction. For the time being, what kind of gains can I expect out of some aluminum heads (leaning toward AFR) and possibly a more radical cam? The previous owner had the engine built, so I don't know all the specifics of the internals. I have just recently got back into the muscle car scene after being out of it for 20 years, so be easy on me. I am also attaching a picture of my ride.

Gun Jam

40 to 50 hp maybe...It depends a lot on the cam you could get more but im not sure how much you want to spend

DIHON

You know what they say: Buy once, cry once.

Gun Jam

yeah but whats good for a NA setup might not be good for forced induction...If you really want to go with a power adder...you should build an engine specific for that power adder.

DIHON

Forced induction will most likely come a few years down the road. First, I plan to do the shock tower delete with tubular style control arms and new crossmember to give me a lot more room under the hood. I will also have to upgrade the 8" rearend before I go forced induction. I would like to maximize the engines current potential, which is why I'm really leaning toward head for the time being.

movielover40

I would take it and get it dyno tested to see what you now have.

Heads and cam aren't cheap.

Don't want to go to radical with cam if your just driving it on the street.

SteveL

You will notice a different with aluminum heads, but exactly how much depends on a lot of factors. Yes, what do you have now? Good advice above and run it on a dyno.
The heads will depend on what you have now. What is your bore and stroke? Has it been changed? It will also depend on what size of valves you use. The easiest ways to gain power is to reduce weight and increase air flow. The heads will flow more freely, so will be an improvement, and with larger valves will again flow better. You can have all of the cool exhaust stuff in the world but if your heads are restricting the flow, it wont matter. If you have a set of heads to look at, look and feel in the exhaust ports. There will be a large hump. Porting the heads will cut the port to the same size as the gasket and will cut that hump down some. Polishing the exhaust side to make it slick and shiny will help it flow, but the intake needs to be rough. The aluminum heads should already be ported out to match gasket size, and should be polished to the correct surface for free flow.
If your looking at forced air induction later, I assume your talking a turbo or a blower. The problem you will find with that is the same problem some engines have with their turbos. You can force too much air in and lift the heads resulting in blown head gaskets. With the forced air you will also need good air flow. If your trying to get a blower to work with factory heads and the factory port sizes it will not be working as efficient as it could be.