I had a page of notes on the subject as I was having issue too. I don't have the notes in front of me so going from memory. I was able to trade my lifters in on 1/2 credit for the Shaver ones. Car is not on the road yet.
There are several issues at play on the subject of roller lifters. Oil band height, oil feed hole height in the block, lobe base circle height and roller lifter quality. All contributing to the same issue with oil pressure keeping the lifter pumped up. The issue is the lifter oil feed may not be exposed to the oil feed from the block the entire rotation of the cam. This in turn is the cause of the poor pump up action of the lifter.
Core shift and different year blocks can deviate the location of the oil feed hole. Larger lift cams will reduce the base circle opposite of the lift side of the lobe to get the lift needed thus dropping the lifter oil band below the oil feed. Many of the lifter makers use a Chevy body lifter that have the oil band in the wrong location. Even with the oil band in the correct location the other issue already listed can still be a factor.
It seemed like there were only a hand full of roller lifter makers for Pontiac. CompCam had their crappy old style. Then they changed to Shaver. I think the Hylift Johnson is pretty new. And then there is the Morels that sell to Lunati and several others.
Anyway the very first post of that thread provides a fix for any quality roller lifter but it requires grinding the oil feed hole up the lifter bore. I will doing this on my next block.
