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.