39 M rear end for pulling

[R Weld]

Got a chance to get a 39 M rear end for a puller. Im trying to make 4500 comfortably and maybe hang 100-200 on nose. I've heard this rear is 200 pound lighter than other M rear ends. Can someone tell me the good and bad? Im running 4mph mostly and 4500-6500. When I get to an engine build, probably wont ever be more than 90hp.

 

[CenTex Farmall]

I don't see where it would be 200lb lighter. It has a slot for the early style seat but that's the only difference I'm aware of as far as structure.

I'm assuming you're planning to go through this thing with new bearings. If you're anywhere near 90 you'll want to upgrade at least the axle bearings to rollers and full complement bearings for the reast.

 

[HOFarmall]

The castings in the 39 and early 40s are lighter. The main housing,trans cover, axle housings and bell housing are all lighter than later models. All the internal parts are the same except the bearing between the input shaft and the upper trans shaft. Most early cases are cracked above the axles but does not seem to hurt anything. 150 to 200 is probably a good estimate.