 Re: GT40P heads?
Doug,
There is alot to consider as far as what heads to buy for your application. How serious do you want to get? Thats a question you need to ask yourself.
I do have a few tips for you.
GT40 heads are wonderful. You can get big power out of them, and they are very easy to find and generally pretty cheap (comparitively) to buy and work on. You can probably find a set of nice, cast iron GT40 heads for around $400. These heads were factory stock on some cars, and all sorts are floating around.
If you want to step it up a notch, FMS offers higher performance "GT40X" aluminum heads, which offer superior flow rates and are made of lighter aluminum. These heads are harder to come buy and more expensive, but are still easy (for shops) to work with.
I'd avoid buying a set of heads that's already been ported, unless you trust the shop that did the work, and the seller has a flow-bench reading and reciept of the work. Do not buy a set of "home ported" heads. They're probably more @#%$ up than improved.
Trick Flow heads are plainly awesome! You can use your stock pistons with TFS heads. You can also use most performance cams, including the FMS E cam you mentioned. That's the beauty of the TFS heads, you get the large 2.02/1.60 valves without having to flycut your pistons or sacrifice cam.
I also suggest that you stick with one brand for your heads/intake manifold combo, they generally match better and flow more that way. If you go with GT40 heads, get a Cobra intake manifold (and have it extrude honed). GT40 intake manifolds flow nicely out of the box, but are near impossible to work on. If you go with TFS heads, go with a TFS intake manifold.
Also, while many people have had great experiences with their E cams, many other people complain about surging problems and other issues. You may want to consider a different cam, though its hard to recommend anything specific at this point. Lots of people love the B cam, too.
I hope that helped. | 
