I am not up on the gmc model numbers, but some of the Advanced Design medium sized and larger trucks came factory with 3-71, 4-71, and 6-71 Detroit diesels.

A 3-53 even with a turbo is not worth the trouble to swap into a truck. Not quite enough power.

However, A 4-53 with turbo is a nice swap in my oppinion.
I am just finishing the tough part of swapping a 4-53T in my 48 Chevy 2 ton.
Search this site for Detroit Diesel if you are interested.
And I welcome any questions on the subject, just start a new thread or send me a PM.
Grigg


•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
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"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-