built both the 100 over the block will be junk next time around sonic check is what i do for the 100 over bore you will see more gain with a 4.250 crank then the small gain in bore size .as a sold flat lifter cam use the face oiling lifter used some wd 40 and some 600 wet dry sand paper . go over the face of the lifter on flat steel or counter top and smooth the face some use moly on cam lobes only check all block bores that lifter truns free use good break in oil