Hah! I have a permanent soft-spot on my rib-cage from playing my T-bird. It's less noticeable these days as I'm playing more ergonomic basses, but it's there. I guess if one slings it low there isn't an issue. There are formula's for pu height, but if it's too close, you'll get 'wolf notes' (feedback/surges) in certain notes. The other concern is getting each string to have balanced output. Add to this that the E and A strings will vibrate/move up and down more than the D & G so that also needs to be taken into account. No wolf notes/surges, balanced string output and you are good to go.