Just the stock ATI 8 rib belt arrangement, with a custom bracket to prevent flex.
There are actually alot of guys making very streetable high HP setups with LSX based engines, especially with turbo systems. I know of at least a few guys in the 1000+ HP range who still drive their cars. Throwing an LSX in a different body style would ease the use of turbo(s), theres bound to be more room. I'd love to do a GN with twin turbo LS1 power. Theres video of a Chevelle running around making 1000 rwhp and it looks pretty streetable. I have read where the owner drives it everywhere.
My car is street friendly, but it is loud (to me anyway, all the other V8 guys say its quiet), but you can maintain a conversation in it and hear the radio. I have made some sacrifices in the name of speed and traction, like ZERO bushings in the rear suspension, all rod ended joints, removed some sound deadening, got a loud ass fuel pump (had to), and I removed the back seat because once the 6 pt. bar went in it was inaccessible. I kept it though, once the boy is old enough he can manage to climb back there, right now his car seat won't fit in there easily though.
Maybe later on I'll remove the A/C and stuff to make it lighter, get some tubular front suspension stuff, light seats, spool, and all the other race stuff and go well into the 9's. Theres a new block out now that will be good to 3000 HP (IIRC) and I think once its become mainstream we'll see 1500 rwhp street cars. The shop that did my car has turned out quite a few 1000+ HP street cars and they get driven, but like I have learned, its useless power on the street. I think after 600 rwhp its pointless.