I have a bolt in 9" from Currie, bought it maybe 13 years ago. I got the drum to drum unit with all the stuff I picked out. It showed up on a crate, I painted it black and bolted it up. AllI had to do was get some different U-Bolts because of the larger tubes and redrill the ubolt plate.
Most car fabrication shops could build you a bolt in rear. Check with Stephen Moore, Cometgt1974 here on the forum he is in NC.
Try the websites for Currie, Strange, Moser or a number of the other companies listed in most Hot Rod magazines. I'd also check with Stephen Moore. Russ Grimes (Joe Dirt), a member here, is in Tn. He has a company called Joe Dirt Fabrication.
from a fellow 70 owner in Northeast Pennsylvania My 9 inch is out of a Lincoln Versailles and bolted right in although it is not a brand new piece