Originally Posted by monty97
Is the 401 flywheel balanced by the extra material at the one end?? Just want to make sure I am not going to screw the 360 up by using the 401 flywheel.
That's exactly what you will do. They are not balanced the same and you'll kill your main bearings. Some specific terminology is being interchanged and used incorrectly in this thread.
are used with manual
transmissions and clutches
are used with automatic
transmissions and torque convertors
Flexplates are inexpensive items. Don't use the 401 flexplate on the 360. Its too easy to do this right. Buy a new flexplate for a late 70's FSJ with a 360 and a TH400 (Quadtratrac) for $40 or less (usually).