Suggestions on rear end setup for road racing
 

I know I can spend $4k and get a whole drop in section, but wondering what else is out there in half that price range that will work?

My last 67 with a BBC I used a 12 bolt with posi, caltracs and rancho shocks and it performed great at the 1/4 mile and did surprisingly well at the road race track as well, though never could get it to stop leaking fluid even with c clip eliminators.

This newly purchased 67 appears to be all stock with a 327 and I'm guessing the puny 8.2 rear. Suggestions on cost vs results, with the idea I only want to do it once with the least amount of power loss possible but not spend a fortune.
No 1/4 miles and probably around 475hp to the wheels. I welcome your suggestions.