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I have a Chevy 1953 Model 3100 5-Window Pickup I am starting the "restification" on. After researching various sources of information, I find I am in need of some opinions. I obtained a parts car (1975 Chevy Caprice Estate 4-door station wagon) from which I extracted
- 4-barrel, 400 cuin V-8
- R400 Automatic Transmission
- 12-bolt POSI differential
- assorted other parts, pieces and thingies

The opinion I am look for revolved around the differential. I plan to order from RB's products in Edmonds Wa, a bolt-in rear end kit (part number 1R-454) to contain the new differential.

Currently the old differential from the '53 measures 62.5 inches from the outer axle end to outer axle, end and 56.5 inches from backing plate to backing plate

The 12-bolt differential measures 65.5 inches from the outer axle end to the other axle end, and 59.5 inches from backing plate to backing plate. (see ascii drawing below)


_ ____ _
| |_____________/ \____________| |
| |_____________ ____________| |
|_| \____/ |_|
^ ^
|---------backing plate---------|
^ ^
|-------------axle end---------------|

Since the plate to plate difference is only 3 inches overall, or 1.5 inches on each side, and the same difference is applicable to the axle end to axle end measurements, and I don't plan to install WIDE tires (not a pro-street restification), does anybody forsee and major clearance problems? I know I will have to have "special" offsets for the wheels to ensure clearance within the fenders and away from the frame, suspension parts, but other than that, is 1.5 inches per side a big deal?

Thanks in advance. :confused:

if you can, get an outside to outside measurement of the rear fenders, that should determine how the axle will fit under them and give you an idea of what your wheel spacing will have to be. if it looks to be a problem there are a lot of nova, camaro and firebird rears out there that are several inches narrower than that full-size rear.

That rear will work but it is a tad wide,tire rub on the edge of the fenders.The front is what you have to worry about if your going to put SBC in a straight axle truck(stock frontend)steering box is real close if you put the motor in the chassis were it belongs.

Maybe this page will help a little. Hey Phat, a guy I know is putting a small block in an 50 Chevy PU.I remember something about using a right hand exhaust manifold from a V-8 Monza or something like that on the left side so the the engine can be set it properly without hittting the stock steering box.You know anything about it? some axle widths