sorry, I haven't been here a while. I directly bolted in 5.0 crane energizers. I spun a rod bearing out of the blue, no idea why. The oil was full and looked good. I didn't have to do anything to bolt the rockers in except make my own bolts, Tom said to rethread the head to 5/16. I didn't want to do that. Tom was buying 5.0 sets and breaking them into 12 piece sets.