The crankshaft on these engines is 1-1/8" x 3-5/32". You can use a longer shaft, but you may have to cut it off or add a spacer at the bottom to keep the pulleys from moving. This engine also utilizes an air cleaner that mounts horizontally so the muffler sits directly under it. If you buy an engine that is not this way, you will have to change it and all the throttle linkage as well.
