Hello. I'm in a state of confusion. I'm looking for any sources on how I can obtain a correct flex plate for my 400 in my 74 Road Runner. The engine has a year "76" casting. The transmission is a Torqueflight.

The terrible vibration the car has, has let to a faulty 360 flex plate that someone drilled to make it work for the 400. The gentleman performing the transmission repair informed me that I need a wide ring gear, 2 weight, offset bolt pattern flex plate that will fit a 10 3/4 - 11 in torque converter.

This gentleman has requested such a flex plate twice and has received the wrong bolt pattern. The piece is for a 360. The supplier instructed him to simply re-drill and adapt to the 400, however, that is already the case.

I appreciate all your help.