Stock 6.1 are probably the best but Johnson Hylift makes some that look good. People have turned 8000 with the right springs.
I called them last month and the guy I talked to said they were still working on a performance lifter?
Do you have a part number?
Crower makes a lifter, but it has a .650" wheel (OE Drag Pak is .700") and not interested in going backwards. Looking at possibly putting in a LS lifter with a .750" wheel from Morel.