I don't know what you'll need to put a 3.73 in your truck since I've not done that. Someone more familiar with swapping rear ends will have to help with that. That particular rear end is very plentiful and I've heard of others who have made the swap. Many Chevy cars of that and earlier eras had that rear end. That's the rear end in my '38 Master coupe. With all of the original drive lines that have been pulled to hot rod the cars, there should be tons available for purchase. I've cruised all day at 65 in my '38 although I prefer 55-60 because it just drives better. Someone who's familiar with swapping pumpkins will be along to give you detailed help on the how to part. Good luck with your project.

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Name your dog Naked so you can walk Naked in the park.