Ian looking for a transmission to make a G25 engine to rear wheel drive.
i an a builder of old ramblers looking for something differant ,has anyone done this conversion before mike

 

It's already intended to be a longitudinally mounted engine. Is it clockwise or counter clockwise rotation? If clockwise, there should be little difficulty here making an adapter plate for your RWD transmission of choice.

If it turns counter clockwise, perhaps you could cut the stock transmission case and run the driveshaft out the rear of it instead of out the front. If my memory is correct, those engines had a separate differential under the oil pan, and not the more common transaxle configuration of most FWD cars.