I have Isky Red Zone solid roller lifters 3472-RH in my hemi. They have needle bearings and were bought in 2006. They didn't offer the bushed lifters back then or that's what I would have gotten. I've sent them back for a check-up twice since then, once in '08, last time in '12. Didn't need anything so back in they went.
My cam has mild lobes and doesn't need a lot of spring pressure...220# closed, 600# open.
I'll be stepping up to a much stronger spring soon, possibly a new cam, and will be sending these lifters back to Isky for yet another check up. I'll evaluate what is needed then.

My KB block has no pressurized lifter oiling. They just get splash and drainback oil. Like said earlier, oiling is rarely the issue w/ lifter failure...it's spring pressure.