At first I would buy two sets of slant six main bearings, and use the upper half of each set. This does require slightly relocating the notch in the bearing cap. Easy to do with a die grinder. But me, being "frugal" did not like throwing two half bearing sets into the garbage, tried something else. I mark the lower, plain bearing, shell and groove it with a die grinder. It is a little crude, but it seems to be working. Have these bearings in my 170 motor for almost 4 years, now, and the 225 in my 66 valiant, for about 50 1/4 mile passes.
