318 stroker

You have to have special 4" stroke, 3.945" bore piston to run with that 4" stroke crank. No normal 318 type replacement pistons will fit because the crank will push them up out of the block. The pistons are expensive, but the crank is the same as the 340 stroker crank and is fairly inexpensive all things considered. Just don't use the Eagle cast version. Factory rods can be used but you will need to notch the bottom of the bores because the nuts of the rod cap bolts will hit. You will also want to replace any 318-type head you might have with the 340/360 heads.