For those prices you can have a 14 bolt with modern (available) brakes.
I’d guess a fair price for the old Eaton with a generally undesirable ratio is $100-150. If 4.10 ratio add some to that.

I have 4.10 in my 1 ton and use it as a truck frequently, in the hills and mountains around here it is not to fast of a ratio, I sure don’t wish for anything slower like 4.56.

•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-