Found the dimensions of the 22xx series motors:
http://www.lehner-motoren.com/ms22_mas.php?la=en

It is physically larger. It is not giong to be as long but it going to be bigger in diameter. I don't know about the position you plan on putting it. It would depend on space.

I'd like to go below the spur gear off to one side where the stock motor's pinion would be... I really really do not want to have to do the huge motor mount with the motor sticking way up high above the spur gear..