car shakes in reverse after 4spd conversion

[challenger57]

My 65 cuda shakes badly when trying to backup. When I first did the 4spd conversion with hyd. clutch set up I tried to use a Ram muscle car clutch set with 3 finger pressure plate. Would not work with hyd. draw cyl. So i went to the centerforce 2 pressure plate but kept and used the ram disc. It goes forward ok but at slow speeds 25-30 I have to keep it in 2nd or it bucks--OD tranny--3:73 gears. I thought the rear brakes where dragging because they would lockup if used hard. Adjusted them loose, no lockup but still shakes badly in rev. I used an e-body drive shaft I had, could it be a little to long. It is a bit of a tight fit getting it in. The yoke is new, could I cut it off about 1/2"? I have to look and see if I have room to slide it in more. Any and ALL thoughts appriciated.

 

[slant6/4speed]

motor/tranny mounts?

 

[Wheel Chock]

If you used an E body shaft, it's too long and binding in reverse. You need to have the shaft shortened to the proper length. Cutting the yoke won't work because it needs the length to compensate for suspension movement.

 

[Supershafts]

It may just be the pinion angle going way out in reverse.

When you go in reverse the diff which is already down usually is going to want to go down further, which would also pull the shaft back. not push in..

If the shaft is to long you should have felt it when launching as it will hit the trans