Well, I've been running bushed Crower bushed lifters for 3 years. My spring pressures are 450 on the seat, 1200 open. My 55mm roller cam is close to an inch. So far I have had no failures and that's what it takes to make a predator engine run. I haven't run 650 open pressures in 20 years but if I did, the needle bearing Morel or Comps would be fine. I had problems with those when I got into the 750-800 lbs range, but I have friends that run the Manley 221424 springs and standard offset Comps and they get 200 passes without a problem. I really like the bushed lifters as if they do start to wear out, they don't deposit extremely hard little needle bearings somewhere in your engine. JMO