Most of the 4.15 stroke aftermarket cranks(until recently) have the stock Mopar rod journal size
that reqires grinding the block on the bottom of the cylinders to clear the rods
I would look at buying a new crankshaft from Ohoi Cranksaft CO.(4.25 or 4.300 stroke with BB Chevy 2.200 rod journals) ground for the low deck and finished to your specs on the clearances on the mains and rods
Very little grinding required on that set up
That also make the rotaing assembly lighter and it revs up a lot quicker and ends up having a lot more torque than the shorter, heavier 4.15 set ups do