A stock '51, 3600 has the same rear housing as a 3800, that is, the Eaton HO52. It uses
an open drive shaft up to the center support bearing. From there it is the same
configuration as the 3100 closed drive shaft but not the same components.
All of the stock half ton rear axles are closed drive shaft all the way back to the rear axle
very much the same as the passenger cars of the same year.
If you keep the stock Eaton HO52 rear axle housing the best you can hope for is to find a
4.10 ratio center section from a late 60's to early 70's 3/4 ton. Other wise you will be
stuck with a 4.57 gear ratio in the 3600.
I have a 4.10 in my '50, 3604 and 50mph is very comfortable and easy on the engine but if
I have to it will run 55 to 60mph but it feels like I'm pushing the engine. It will run up to
65 or 70 but I'm afraid that a splash feed engine would not last to long at that speed before
it put a rod thru the block.
Denny Graham
Sandwich, IL
Last edited by Denny Graham; 10/04/2011 12:55 AM.
