The smarter way to make more HP and torque is to have your existing crank offset ground down to BB Chevy rod sizes and increase the stroke to either 4.250 or 4.300, then buy the cheaper BB Chevy rods in the 7.100 long with .990 pins and have pistons made for your bore size. Probably to late now, huh Next time
Some blocks will need a little (.030) grinding and others will need closer to .060 to clear the rod bolts to the oil pickup boss