I am in the process of putting a Detroit Diesel 4-53T in a 48 2 ton. I have seen a few DT466 engines, and think you will have a very hard time getting it to physically fit in the sheet metal. My 4-53T will be about as tight a squeeze as can be done without much, or any, body work.
But like they say, nothing is impossible, just throw enough money at it..
Now think about this, can you unscramble an egg? Perhaps some things are impossible?...

•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-