My 1997 4.6 Windsor motor( AT) failed. I picked up a 4.6 Windsor from the junkyard. It was out of a 1997 MT but the motor was a factory re-manufactured motor. My problem is I was just going to swap the fly wheel for my old flex plate. But my old motor is a 6 bolt the new motor is an 8 bolt crank. Where can I get an 8 bolt flex plate for a pickup? Is there any type of issue with balance weights on the flexplate or is it standard with no variation. If anyone can please help me with info and a source for the plate I would greatly appreciated it.
Dave

 

The only A/T flexplate (4W7Z6375AA) listed for an 4.6L F150/250 or E150 has 6 bolts.

 

Modulars are ALL internally balanced,so there's no weighting issues to be concerned with. There is an 8-bolt modular 4R70W flexplate available-you might have to request one for a 5.4L instead of a 4.6L. My '98 model 4.6L/4R70W truck had an 8-bolt crank in it,so they did build them that way,and the parts are available-you just have to know how to find them. Some dealership parts "experts" have issues finding less common or obscure parts.
JL