The set I'm considering are several (5+) years old, but brand new in box. I realize this is a relative question, but I figured one of the engine builders would say 5 or maybe 600 lbs would be the limit before looking to jesels or similar. I think for a decent hydraulic or small solid roller I'll be looking at 400+ open, and thought I'd see if there were a consensus on the limit of an aluminum body rocker.