Wait till you see what I find....

If it is a factory roller cam motor, 7.50" pushrods are too long. You best check that. you may end up with the same issue.
let me repeat that is the wrong pushrod length. If you are using a seven and a half in length pushrod that is way too long. You need the push rods from a 1990 360. They are less than 7 in Long.

I looked back at the prior thread on this.... original cam was a hydraulic flat tappet. OP changed to a custom roller cam. OP, please take note of the above. (Unless you found some roller lifters that are exactly the same length as flat tappets, or there is something really different here that we aren't aware of.)