from the way i understand chuck, is the lifter bores need to be bushed to control the oil. Its not the mod thats the issue. Sometimes a roller lifter with a high skirt can dump a lot of oil out of an unbushed lifter bore when it uncovers the oil galley while on the nose of the cam. I had this issue with a SB once and after 3 sets of different brand lifters I found that the Morel lifter fixed because it had a lower skirt that kept the oil galley covered at all times.. Chuck didnt explain it that way, but i think thats what he meant. My other block is bushed, so i may use them in it if the issue arrises.