To clarify the difference with the crank the left with the shorter shaft threaded to the end is the stock style and the one on the right is the style of the crank the came in the new engine. Both engines are SH .21 and both have same crank case size as far as length, width and height so I don't feel its a problem with the crank. These pictures are just examples of the different shafts, physical appearance of both cranks that would be inside the engine appear to be as close to being the same as possible from what I could tell looking at them. I was sure to closely check them both and compare before attempting to put the old crank in the new engine