I have a '49 axle with a '57 center section. In your case I believe you can do the same, just keep your '53 axle, lose the closed driveshaft and pumpkin, insert the '59 differential, get an open driveshaft transmission and driveshaft to fit. I burned off the '49 pivot and welded on new spring perches at the proper drive angle. Your choice.
As was said previously, you don't gain much, I went from a 4.11 to a 3.90 as you would if you did this swap, but it then became open drive. I use a .70 overdrive. Here's the math, .70 X 3.90 = 2.73, final drive ratio. I go 75 mph no problem @ 2100 rpm's with LT 215 85R 16 radials.
~ Cosmo
1949 Chevy Half Ton
Rocinante, like Don Quixote, he is awkward, past his prime, and engaged in a task beyond his capacities.
"...my good horse Rocinante, mine eternal and inseparable companion in all my journeys and courses." ...Don Quixote, Cervantes
"If you come to a fork in the road, take it."...Yogi Berra
"Rudeness is the weak man's imitation of strength." ...Eric Hoffer
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