The first thing I would do is call Speed Pro to find out whether those pistons have a solid dome or a hollow dome. I am sure it would be cheaper to mill the domes until the pistons are flat. Their flat top pistons have a piston head volume of 6.10. While having the domes whacked off the pistons get the machinist to square your block and mill the decks to zero. Then you can use a stock head gasket with a .039 or .041 compressed thickness. As for heads I would get a set of Promaxx aluminum heads with 72cc chambers. After everything is said and done you have a compression ratio of 9.325.
ProMaxx Performance 2171: 185cc Aluminum Cylinder Heads Small Block Chevy | JEGS
