Alright heres what you need to do;

Transmission Diagram

Cross View

Scroll down to the bottom and use the listed numbers to check out the section in the parts book to find the numbers you need.

So if you want the clutch main gear bearing (diagram # 4.355) you check out that number according to the master parts manual which puts you here. Look through the list and find the appropriate number related to your truck and tranny, which appears to be New Departure bearing # 3209-L. Give that number to any good bearing seller and they will cross reference to a newer number or if it hasnt been changed after 60 years the same number, regardless of number the bearing should be the same if it cross-references.

A little time consuming when you dont have a manual on hand, but it works.

Good luck, let me know if you need any odd parts and I can pull one of mine apart.

Jeff

My 1953 Chevrolet
1947.1 Gallery
1972 C-10 1/2 Ton & 1972 C-30 1 Ton