I popped the 4-speed muncie out from underneath the car in about 2 hours. If you only are working on the tranny then that is without a doubt the easiest way.
Just jack the car up, pull the driveshaft, disconnect the speedo, remove the starter, push the tranny crossmember out of the way and drop the tranny out.
'68 428 HO M3 Monster, 4-on-the-floor! Need I say more?