Im in the middle of purchasing a used 1970 472ci caddy motor and its TH400 trans for $500. The car runs, and good, and I'll be stealing the 4-core radiator as well. I would love to stay with a manual trans but the Caddy motors don't match to Chevy trans, so that means finding a stong enough manual trans and buying the $250 adapter and $200 flywheel to make it work. Too much money for me!!
My 59 has the 3.92 posi factory rear, so I should be safe there. This motor stock is rated at 375hp and 525ft-lbs of tourqe. With an eldebrock intake you're at SBC wheight!!
I'm in Arizona and this old Caddy parts guy has MANY 30's-80's Cadillac motors rebuildible or running. So with alittle drive shaft work and motor mount fab I'll have myself a real mover!
Hang on to your stovebolt though, they're still the best from the 50's!!
Whatever you buy make it older than '73 so the power is decient. I like buying running motors for 2-500, and a SBC rebuild is the least expensive way to go!
Good luck,
j
