This has been covered many times in many places.
They have two case gaskets for 1122 saws.
Most take a regular 066/660 oil pump but the 064. They look like an early 044 10mm saw oil pump with panel air filter. Old school.
064-066 or an
066-660 and 650 case gasket.
One has a shorter oil tank.
Overall they had four different case volumes that DD covered extensively.
The cylinder base gaskets are the same for 54mm 066-660.
The seals can be an early or late model set. The late model has bigger seals. The changer saw, I own one, is a flattop short case 066, no decomp with cast metal flywheel vs the poly wheel later with a long oil tank 066/660 bubble top with a decomp button. The early coil is different and so is the early redlight coil on the red eye 066 from the old model. Ignition limited setup for tuning purposes.
The early 064/066 had a panel air filter not the HD type. Most of the new 066 models have and HD filter with a metal housing different from the 064 metal housing and metal air filter cover. My saw has the HD filter on a metal base with a plastic cover shaped like a plastic HD 044 cover. Yup, clear as mud
The rest should be the same except carb kits. They had two or three Walbro models and a Bing early on on several models.
Hope that helps.
