Ok, so I'm going to be running a toploader behind my 351. The engine was origonally an automatic. I hav'nt inspected the end of the crank, but do ya'll think that anything will need to be done back there? Thanks alot!
Cranks are the same...but the bolts that hold the auto-flywheel are not long enough for a 4-spd flywheel. Easy to find at any car / hi-po shop ... just get the right one because these need to be the strongest grade possible...there is a lot of force on those few little bolts.
Other weird things I ran into - some obvious, some not:
crossmember - different for toploader
speedo cable - different for toploader - longer and exits pass side instead of drivers side
drive shaft - a 4 speed shaft was fatter stock, so it used a different yoke on the rear end. I had a 9" to begin with, but I needed to get a special u-joint to make it fit.
firewal seal - clutch linkage exits the firewall right next to the steering column - and there is a rubber seal there to keep out the elements...good to have if you can get it