I had these Diamond Pistons #83166 made for a 3.79 stroke 340
Pin height:1.400
Bore 4.070
Dish 9.3cc
Rod 6.300in SBC

These pistons are .005 down the hole and will give you aprox. 10.75 comp. with a zero deck a .040 head gasket and a 65cc chamber head. Makes 394ci while still maintaining a good rod to stroke ratio.