Morel hydraulic roller lifters are made with the oil band lower on the lifters, so they can be used as retrofits. I used them in my 273, but mine are bushed because one lifter bore was worn WAY too far and a few others were marginal. $1K is about the going rate to bush the bores using a BHJ jig. Don't let someone do it with one of those Mickey Mouse things with a hand drill that will result in the lifter bores headed in 16 different directions.