Clearance for RPM Air Gap...

Ok Seven I'll bite, lol
I once had an engine like your son describes. It was a 318 with a 340 top end and cam.....And 2.76s..... It was all noise and posturing until 50/55 mph at the top of first. Then into second it was back to a whole lotta noise and very little go, until about 80.
Unlike yours, mine sounded like a really really low-compression built-from-left-over-parts,pos, teener....... which it was.
I agree, some combos just shouldn't be screwed together.lol