Rear end ratio change?

[Powerhouse]

Howdy all,  

 

I have a 3.9 that seems a bit sloppy.  A lot of movement before it moves the wheel.  The tire moves about 6 inches before it turns the shaft.  Is that normal?  All the seals are in need of replacement.  

 

I was wondering if it were possible to change the ratio to something like a 3.73 by swapping out ring and pinion.  I don't think I can do the rear end swap to a cherokee or whatever.  Shouldn't be too hard I guess, but finding one is not easy.

 

 

[Young Ed]

No its not normal. It should move very little before moving the wheel. You are better off swapping the entire assembly. You can put a 3.73 in but the majority of them seem to be from later cars which requires swapping the side gears out so they match the # of teeth on your existing axles.

[Powerhouse]

OK.  Thanks much.  I will look into parts cost.  I am guessing a 218 should be able to handle the 3.73?  Since they were available in sixes.  I have 97 mustang t5 in the car now behind the 218.  

[Young Ed]

OK.  Thanks much.  I will look into parts cost.  I am guessing a 218 should be able to handle the 3.73?  Since they were available in sixes.  I have 97 mustang t5 in the car now behind the 218.  

I have a 3.73 in my p15 with about 20K miles on it. My stock 218 handles it just fine. I do notice needing a little more clutch on a really steep hill with a stop sign but otherwise its great. It still works great now with the overdrive I installed last fall.

[40phil41]

I have 3.73 gears in my '41 Dodge (originally 4.11). As mentioned above, the axle splines on the '54 3.73 are different than those on my '41. I ended up also doing a small bit of machining to get everything to fit in my housing (can't remember the details). Runs great.

 

Phil

[Powerhouse]

Thanks guys.  I haven't found and gear sets yet but will look some more later.