Hello,
I have a 1964 Mercury M-250 4x4, with a low pinion Dana 44HD. I have swapped out the rear axle for a later model with 3.73 gears. I can now drive my truck at a pretty comfortable speed. Looking to locate the best place to source a new carrier and a 3.73 gear set for my front axle. Most place only offer these parts for a high pinion axle. Does anybody have any suggestions?
Thanks,
John

 

Where will you find a front driving axle 3.73-1 R&P and case, since FoMoCo never offered this ratio for 1959/68 M250's, 1959/72 F250's?

Only ratio available thru 1965: 4.55-1 .. also available thru 1972. 1966/72's were also available with 4.09-1.

 

Check out Randy's Ring and Pinion. If it is available any were they will know.

 

Ford F-250 3/4 Ton Front Differentials Dana 44, 19 Spline Ring & Pinion Sets
You will also need a different carrier for 3.73 and down (numerically) gear ratio,
Ford F-250 3/4 Ton Front Differentials Dana 44, 19 Spline Carrier Cases

 

The nice thing about Randy's is the kit is complete with instructions and even the paint to set up the gears. They make it so easy.

 

How many splines does the front driving axle pinion gear have for 1959/72 F250's? 10

 

Thanks for the information. I understand the truck has 19 spline axles, based on some assumptions. I will need to breakdown my axle to be 100% sure. I will contact Randy's and see what ups.

Thanks I was hoping this wonderful resource would come though.
John

 

Uh huh...I found out well over 45 years ago, that with FoMoCo, you cannot assume anything!

Look at the two pics for 4851 .. the companion flange that the splines of the 4WD's front driving axle pinion gear fit into.

1959/72 F250: It's C1TT-4851-F .. 10 splines.

 

Wow, nothing like crashing the party Numberdummy! Got any suggestions? Should I look for a 73-78 Dana 44 with the correct gear ratio. I worry about fitment issue mainly steering linkage. John

 

Pull a shaft and see what you have.