1972 Demon 4 speed

No offense but sounds like more than 10% fall into that "not so good" category .... as a current certified mechanic I can tell you it's hard to tell what driveline noise is normal while under no load. I've ran enough cars in the air to say most seem "sloppy" and sound like they're gonna fall apart, especially while the suspension is at full drop. Your best bet is to take it for a spin and see what else you find.