64 pushbutton tranny to 66 slant six

Yes the pushbutton trans will fit the 66 engine. It will fit all slant six engines. On a 68 and newer slant, a 68 up flexplate, and a adapter bushing in the end of the crank is required. I have the push button shifter on a console between the bucket seats in my 66 Cuda. I also have one in my 65 Valiant. One thing to consider, for a race car. The location of the PB's in a 64 Valiant make it difficult to shift, with a manual valve body, while seat belted in.