price to narrow a B body 8 1/4 rear

I saw this deal, I thought, on a 8 1/4 rear from a 71 b body. It won't fit an a body w/o some narrowing. Place I called here where I live said cost would be around $1000. LOL, for that price I can get a 8 3/4. Does 1 grand sound about right? Thanks.