That's odd the rear track would be narrower than the front. One would expect wider in the rear if not the same. Differing size wheels/tires is more common today - as are directional tires. Back in the day the OEMs preferred same size tires with a full size spare allowing for a circular 5 tire rotation regimen.
Yes. The 3.55 ratio was created for the Power Glide transmission which was introduced in '50 along with Bendix brakes. The third members are completely indistinguishable so the PG units carried a ratio tag:
In the factory they placed them on the drivers side bearing carrier bolt. I placed it on a banjo bolt at 2 o'clock (to telegraph the swap to the detailed eye). The is where GM placed these later on when many ratios where offered:
During assembly it was important to know this detail because the correct speedo gear had to be fitted to the transmission during assembly.
Chevy also offered a 3.73 ratio starting in '40. But these are rare. I once saw business coupe at a show that claimed to have be so equipped - (for efficient long distance travel of a Salesman).
