Also told me they never saw an issue with a 318.

Yep, ive a 76 318 block they will not work on, It had never been apart before I took it apart and the lifter bosses have a huge chamfer? at the top. A .500 lift roller wont even fly on my block.

Where my 73 360 block is over 3/16 taller in that area with no chamfer/bevel.

What sucks for me is I wanted to run a hydro roller in my 76 duster block but am limited to a full body solid lifter/cam.