New engine issues

At this point, I guess I’d try a different carb, verify the lifter preload, timing curve, cranking compression, and vacuum at idle(see if you can borrow another compression tester and vacuum gauge to verify your readings).
If everything checks out the same, and the carb doesn’t help at all...... I’d look into a cam swap to something with much less advertised duration....... like a Comp 260H.