Is this a trick question?
There is no such truck.
It is ether a 1954 1/2 ton truck. enclosed drive shaft.
Or a 1955 1st series truck. Open drive shaft.
Unless I missed something.
If it is a 1954 1/2 ton truck with the enclosed drive shaft.
You could try this trick:
Alignment Solution for Installing a Late Model Rear End in a 1947-1954 Pick Up.
On the original rear end, the spring centerbolt is offset to the front of the spring by 2"to 3". If you install a modern rear end (with an open driveshaft) and retain the original springs, the wheels will end up offset forward (inside) of the original wheel openings in the fenders. To correct this problem, remove the original springs and reverse them end to end (front to back) as they are the same on both ends. This will bring the spring centerbolt to the rear of the axle and place the new rear end in the center of the fender wheel openings. Jim Carter Tech Tip with picture
Tim Lederman & Greg_H are correct, in order to install a 3.55 ring gear in the 1954 1/2 ton 3rd member/carrier housing.
You have to use a 1940 to 1953 Chevy 1/2 ton differential carrier/spool case.
part number 3652336. Master parts Cat picture.
Group # 5.510 MPC Part
So that the ring gear bolt pattern lines up with the bolt pattern on the differential carrier/spool case.
MPC also indicates the 55-57 1/2 ton O/D.