The bellhousing that was found behind 318 Poly engines in front of 4-speeds in the early '60s had multiple bolt patterns and I believe bolted to a flathead six, the slant six and the LA. I cannot remember if it had the pattern for a 3-speed on the other side. The bellhousing itself weighs about 70 lb. It pretty much encloses the flywheel down about 2/3 of the way.

R.