Assuming you have a late 47 truck?
Can you swap to the SM420 and also swap the clutch and brake pedal assembly from a 48-53? and if needed shorten or lengthen the first section of driveshaft?

I don't think you can swap parts inside the two transmissions.

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-