The 1966 transaxle will not work in the 1964 Corvair. The 140hp engine can be adapted to the 1964 Corvair, but the 1964 differential needs to be retained to support the swing axle design and the unique (to 1964) transverse leaf design in the rear suspension. The 1965 (and later) engine sheet metal around the perimeter of the engine was redesigned to match the new body and engine compartment that was introduced in 1965. The perimeter engine sheet metal from the 1964 and earlier body style would have to be modified to provide for the additional two secondary carburetor intake manifold mounts. The 140hp bell housing, clutch and flywheel and associated hardware would mate to a 1964 differential and 1964 manual transmission.6Gun_Joe wrote:I came across a seller with a 66 140 engine, and a 3 speed transmission unsure what year. What would I need to put those into my 64? And would the 3 speed work with the 140? I assumed the 140s came with a 4 speed.
There are some variations in the rear engine mount bracket, as shown below. The original Early Model bracket was very close to the crankshaft pulley. When the crankshaft pulley changed to a harmonic balancer in 1964, the added thickness of the harmonic balancer was so close to the bracket that a fan belt could not be mounted. The shape of the engine mount bracket was changed to provide for more clearance. This new shape was retained in the new two-hole design introduced in 1965. The added clearance was also needed for air conditioning or smog pump crankshaft pulleys.