Yes,the Shay is easily convertible to an automatic.The hardest part is finding a Pinto or Mustang II for a donor car.You really should buy a whole car for the parts.That way you can get the flex plate with the correct bolts,correct rear mount,plate for the back of the engine,all the right bolts,and I can't remember right now,but I think the starter is different.I think you will have to change the driveshaft yoke also.If you just buy a transmission and try to put it in you will spend dozens of hours chasing down the little parts.The shifter is just a flat plate mount,bolts to the floor,and operates by cable.If you were going the other way you would have to deal with the clutch pedal,linkage brackets etc.I can't remember right now if that transmission uses an external oil cooler or not.If it does that is a minor addition.I'm almost thinking they don't use one.I should remember,I changed dozens of them in the 70's due to a freeze plug problem.