Rear End Swap
Fleet Mechanic
Joined: Jan 2011
Posts: 1,793
Likes: 74
From: Richland, WA
Yes, Ford started offering 3.73s in '97, but in the light duty F250, not the heavy duty OBS. If you had a '97 PSD (which only came in the HD) with 3.73s, then someone must have swapped them in, like I did. Finding a 10.25 with 3.73s will be nearly impossible. A 10.5 with 3.73s is very common, but the bolt pattern is different and the spring perches and shock mounts would have to be moved. Then you'd also have to change the front so that you're not running 2 different bolt patterns.
That being said, I love my 3.73s and will never go back to 4.10s.
So your options are (easiest first, IMO):
1. Get a complete 10.25 axle with 3.55s (direct swap)
2. Get a 3.73 ring and pinion from a SD 10.5 (or after market 10.25 gears) and swap them in.
3. Get SD front and rear 3.73 axles and move the spring perches and shock mounts.
If you're not really good with a wrench and willing to do lots of research on gear swaps, then number 2 gets moved to the bottom.
That being said, I love my 3.73s and will never go back to 4.10s.
So your options are (easiest first, IMO):
1. Get a complete 10.25 axle with 3.55s (direct swap)
2. Get a 3.73 ring and pinion from a SD 10.5 (or after market 10.25 gears) and swap them in.
3. Get SD front and rear 3.73 axles and move the spring perches and shock mounts.
If you're not really good with a wrench and willing to do lots of research on gear swaps, then number 2 gets moved to the bottom.
Hotshot
Joined: Jul 2008
Posts: 11,231
Likes: 130
From: Thomasville, GA
You're a little ways away, but shoot me a PM if you are interested. I could pull the gears if that's all you want.
Thread
Thread Starter
Forum
Replies
Last Post
