if you want to do this, id use the carrier shims from the 4.10 axle. Reason being 4.10 is going to be a thicker gear then 3.73, But not by much.
Swapping gears is probably harder then doing an engine swap. I dunno, never done an engine swap. But im sure if you knew what you had to do, exactly what you had to do before you had to do it, that it could be done.
now im going off the fact that the shims in the stock differential are ONE nice Peice. So bascially ford makes these things to be bolt-in at the factory; All the stock shims are closely the same size
try this... Measure the length of BOTH carriers (TO THE HUNDREDTH OF AN INCH! so you cant use a regular ruler, you need something special) and see if there is a difference between the two. Like a .005 of an inch is a difference.
if they are different in length then you can forget it... you need to research how to do it or get it done perfessionally, swap the axles or SOMEthing
If they are the same in length, then you can probably get away with using the shims from the 4.10 axle, to line up the LSD (3.73) carrier correctly
The Pinion (shims/bearings) from the 4.10 should be fine, assuming the center line of the axle tubes relative to the pinion bore is the same on both axles, in other words aslong as the pinion depth doesnt change.
You WILL need to research setting pinion bearing preload so you can install the pinion correctly.
i dont know if my method would work, since the housings can possibly be a different in size ever so slightly. Ive never tried it like this.
