If you need to grind away at the cylinders bottom for rod clearance, that’s about it besides the cost of the crank and pistons themselves. Rod choice can keep costs down and between the 4.00 & 4.00+ cranks, the rods can be the same. It’s piston differences that can be more money. The added stroke of .15 or .18 or .25 will need to be addressed at the piston.