I am using the 1951 Ford car rear axle that came with my '51 Muntz Jet (all Muntzs came with Ford rear axles). The gear ratio is 3.73 which I believe was standard in non-OD stick shift Fords. I am using a '51 Ford F1 3-sp. Both the transmission and axle ***embly have been completely rebuilt, except the ring and pinion gears which are original. I am, at this point, not going to swap out axles from other cars. What options do I have for numerically lower gear ratio, if any. Are there after-market gear sets? I would like to get to around 3.5 or so.
I believe the highest is a 3.21 found in 56 p***enger cars minus the wagons, Birds, and pickups that used a different style. 49-56 were essentially the same. I’m sure there was a set near 3.50. 55 p***enger cars had a 3.31.
My '51 with a stick shift (no overdrive) has a 3.55. The car was very original when I got it, and I counted the teeth when I dis***embled and painted the rear axle. I believe the Ford-a-Matic equipped cars had 3.21's.
The removable-carrier cases were actually color-coded in '56. The lower ratios (4.11, 3.89, 3.78) were painted black, the 3.55 were red, and the 3.22 were gray. I suspect that was true for the earlier years too, but don't have those manuals to verify that. The 3.22 and 3.55 were only available with the Fordomatic, both sixes and V8s.
I used a 1954 3.54(5) in my '51 many many years ago. Ya need to swap the axles too as the later cars had a finer axle spline, and that's a good thing! Dave
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