Isky EZ rolls do not have needle bearings to distribute in the engine when and if they fail like other lifters do. I have run them for two seasons now but I replace them every season and have them rebuilt by Isky for the next season. I have 360# on the seat and somewhere near 1068# or better on the nose with .920" lift using 1.8 ratio rockers in my 12 degree 582. I change them every season no matter what any one says because I own the engine and pay for the damage if I save $400+ by not changing them out, when I can send them in and get them rebuilt for half the new cost. I think that it is dollar stupid and penny wise to not replace them. My engine is worth more than my car chassis is so I respect my investment by using what I hope are the best products and change them out annually. I think that the EZ rolls are great so far. I run near 130 passes on them per season and have had no indication that they are unhappy in my engines environment yet.
Bruce