stroker 318

It's a 318 with a .40 overbore and a 4 inch stroke scat crank and rods with icon forged dish pistons to keep compression down, small comp magnum 270 series cam, the heads have 360 intake and exhaust valves in them with a port and gasket match. I have read the magnum heads were'nt much better then the original ones other then they have a smaller combustion chamber, but need alot of porting to make them flow well? Just what I read.. I do know the heads I have are small for a stroker engine but I was hoping with the larger valves and port work they would work until I could get another set. I have read the articles on 400hp 318's an I was'nt trying to get 400 but it would be nice if I was somewhere close within 50hp or so. As for the compression ratio I think icon dish pistons have 9.5 with 62cc chambers but I'm not sure and I'm not saying that's what I have.