[JWHboise]

I have a 1951 GMC half ton 5 window with a locked up rear end.

Will a 1957 half ton Chevy pickup rear end be interchangable with the GMC????

Thanks in advance for any info on this!

[DeSoto Frank]

Depends...

Back in the '50s and earlier, there were more differences between Chevy and GMC than just the badges.

If your GMC has an enclosed driveshaft ( "torque-tube"), then you're going to have to find a rear from a pre-'55 GM truck. Another wrinkle - GMC made a "heavy 1/2-ton", which rode a longer wheel-base than the Chevy 1/2 ton ; those trucks have a longer driveshaft.

I believe the '47-'54 Chevy 1/2 ton rode a 116" wheel-base. If your GMC has the 116" wheelbase, then probably the rear-axle from most 1/2 ton Chevys will work.

One more note, in 1952, Chevy switched from Huck brakes (two adjusting slots at top of backing plate) to Bendix brakes (one slot at bottom).

After GM brought-out their "second-series" trucks in mid-1955, they went to conventional "open driveshaft" in the 1/2-tons.

[Bob Call]

JW

If your Jimmy is a Series 100 1/2 ton, manual transmission, my Hollander interchange says that the 48 thru 54 (that would include 1st series 55) Chevy 1/2 ton is the same as the 48 thru 54 GMC. I believe the Chevy 1/2 ton is Series 3100. The torque tube should be 60 5/32 inches long. Trucks with Hydramatic trans have a different rear axel assembly.

[bebe123]

This project is possible but requires lots of hard word as these vehicles have more differences in the 1950's model.