To Stroke, or not to Stroke

The blk is a 4006530-400-3, I am thinking the bore was around the 4.325 or very close to it. I can find out for sure. I can get the .30 in the 400 in KB forged here in town for $509, 440 source wants $546. I am open to any and all suggestions on piston choice. I want a good strong piston but can't afford to get radical.