Stroking a 318 to a 390

I've gotten in the habit of mocking up all the stroker kits. Of any displacement. Some say they are fine - but when I get them they are not. Be it the tangs on the bearings or rod, the design of the crank, just the Universe working against me... I end up with hard to turn and no side clearance. Usually it's just some chamfering of the bearings are required. No big deal, but much easier to do as you go.