BTW, are those pistons the Diamond S1010 model? If you take those and 63 to 65 cc heads, and deck the block around .020" to get quench, then the SCR will run up in the mid 11's but the DCR may work out decently around 8.0 with that big of a cam.
Looking at either the dia51010 or dia51009... only difference is the pin size and I have no idea which to go with. These had the highest compression figures of any 40 over stroker pistons I could find...
Diamond Racing Pistons Mopar 340 Forged Piston set, flat top, 4.080" bore (.040" over stock size), 4.000" long stroker, 6.123" rod, 10.9-1 compression with a 65cc chamber. This set uses a .984" dia. stock small block Mopar size piston pin. Piston set includes pistons, piston pins and spiro locks.