Your uncovering the oil galley at full lift just as you said. I had same issue with my SB. I had to find a lifter with short skirts/windows to fix the issue. I tried comp, crane and morel. The morels fixed the issue and turned out to be a very good solid roller lifter running on .714" lift on the street. I used them for 10 yrs rebuilding them every 5yrs. The car doesn't get a lot of miles on it thou, but the miles it did get were hard miles. I thing I paid $250 for the set at the time thru Erson cams.