My advice is tell the place you buy the forged internals from what your plans are. They will advise you on what type of pistons to buy. Remember, compression has to do with how much air/fuel mixture is "compressed". This is why if you use "dished pistons" as opposed to "flat-top" pistons, there is more surface space in the cylinder and thus, the more air/fuel can be compressed within each cylinder. I recommend talking to CobraKiller(Tim) at Modular Ford Powerhouse. Talk to the guys at VTEngines and Modular Depot as well. They'll hook you up with exactly what you need for your application.