1.) Look at this shop manual. It's not for 1953 but 1951. Start with section 4-10.
http://chevy.oldcarmanualproject.com/shop/1948_51truck/index.htm

2.) Look at the 1929 - 1957 Chevrolet Master Parts & Accessories Catalog.
http://chevy.oldcarmanualproject.com/1929_57chevyparts/index.htm

The attached illustration is for a 1-1/2 ton truck. I could not find an illustration for a 3/4 ton that includes the axles.

The gasket is a problem. I believe the part number is found in section 5.811 and my GUESS is that the GM part number is 3680995.
This may be a spacer and a gasket (soft alloy metal). I would not use regular gasket material here. Hopefully someone in this forum may
have some experience that they can share. You may have to reuse the old gasket/spacer. This is not the same paper gasket that goes
between the axle flange and brake drum. Take a picture of your gasket/spacer and post it.
Attachments
1948-53 Rear Axle 3600 Pic 04.jpg (159.69 KB, 48 downloads)
1948-53 Rear Axle 3600 Pic 05.jpg (45.6 KB, 45 downloads)

Last edited by buoymaker; 09/22/2020 6:59 PM.
"Adding CFM to a truck will only help at engine speeds you don't want to use."
"I found there was nothing to gain beyond 400 CFM."