I Have found roller lifters for a 95' 3.1L chevy, a V6-60*.
They have round OEM roller lifter with a plastic holder that holds the top of the lifter and the plastic holder goes in the middle of the block and push rods.
Do you think they would fit a 95 3.4 block?

 

The lifter bores in the 3.1 block are higher than in the 3.4 to give more support to the lifter. I don't believe the 3.1 lifters are a direct plug in. Check around, there are several mfg's for roller lifters than do work with the 2.8/early 3.1/3.4 blocks, but I think most are mechanical, not hydraulic.

You aren't planning to use the rollers with the H-272-2 flat tappet cam are you? You can't do this!