if the rod journals are stock Mopar 2.375 size I would sell the rods and pistons and have the crankshaft offset ground to BB Chevy 2.200 size and offset to 4.300 stroke and buy some BB Chevy 7.100 long rods with the .990 pin size and buy a really good set of a lot lighter piston and pins
What size rings are on the pistons you have now?
If your going to race this motor only look at a skinny ring like 1MM,1Mm,1.5MM in all three grooves, not 1/16,1/16, 3/16