Lots of BBC into TF out there. It's more of an adapation than a swap. I put one from a 72 C20 with TH400 in my 57 last year. It is a 3600 and had a 235 w/4 speed hydromatic.
1. remove everything from firewall forward, sheetmetal, engine, etc.
2. 'hang' the new engine/trans with motor mounts and manifolds on it in place on hoist as low and starboard and aft as you are comfortable. maybe 1 inch from the frame, firewall, steering gear, etc.
3. build some motor mounts from channel, or buy a universal pipe type, and a transmission mount.
4. measure and build a driveshaft. I was lucky the open shaft from the hydro mated with the output shaft from TH400 via a U-joint.
5. build/adapt a transmission selector lever. The hydro column selector made it easy.
6. build/adapt a throttle lever/cable.
7. fabricate a couple exhaust pipes that will fit.
8. carfully fit the old cooling fan to the waterpump in the inch or so you have allowed for the radiator, add a transmission cooler.
9. adapt some radiator hoses, fuel lines,
10 hook the HEI to your ignition switch and you are done.
