Originally Posted by sixtysevenGTconv
I have an M1 in my 67 390 car.
I wonder about trans mount flanges to bell housing size? It maybe also longer meaning changing out driveshaft?
Minor this as said, need a trans shifter mount plate to relocate shifter? Maybe.
Longer speedo cable as M,M1, M2 all have cable going in on rh side of trans.
Trans mounting cross tunnel brkt is different for 390 trans.
There are two length Toploaders, the 14" tail, which is this unit, and the 17" tail, which is used in full size Ford/Merc as well as certain Torino/Montego applications. Only difference between the small block and 390 unit is the input shaft is shorter on the 390.
Could use the Hurst shifter for the '67 390 Mustang, or I believe the two untapped holes by the tail bushing can be drilled and tapped to allow use of the small block shifter. There was also an adapter plate at one time that allowed the use of the forward pattern with the small block shifter.
All toploader speedometer gears are on the passenger side and require the long cable.
Toploader uses same trans crossmember as the C-4 and 3 speed with a small block. 390 toploader crossmember is different, but because of the engine, not the transmission.
That said - $1400 is a lot of money for a toploader you need to swap the input shaft on to have it work correctly.