I've talked to folks who mistakenly call the SM420 4 speed a 3 speed either because they can't find 1st gear or figure it's so low it's not useful... therefore it must be a 3 speed with granny gear( if they happen to find the real 1st gear..)

In reality the SM420 is a 4 speed with reverse.

Grigg

•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
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"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-