I've got a '95 F150 XLT SuperCab with 5.0L and E4OD. It currently has a 3.31 non-posi 8.8 rear axle, with the pinion bearings going out (99k miles, it's been noisy since 92k). I'm waiting until next month to fix, when I have $$$. It's not being driven much right now, to save wear and tear. I'm trying to decide whether to get the current axle rebuilt with a posi unit and staying with the stock 3.31 gears, or swapping in a complete axle. So, questions:

1) Can I use an 8.8 rear axle from a 97-00 model? I know that the newer ones mount the shocks behind the axle instead of in front like mine, but some I've seen have brackets with two sets of bolt holes, maybe for front or rear shock mounting? Also, what about the RABS pickup connector on these? Same as mine?

2) What kind of rear axle is it I've seen on some SuperCrews and newer F150s. The carrier housing looks like the one on the SuperDutys. Is it some kind of Dana, and is it only used on ones with 5.4L engines? Would this swap in?

3) Is it true I don't have to worry about the speedo when changing ratios? I know the speedo picks up its signal from the RABS sensor, and since it's on the ring gear, it's measuring wheel speed, not driveshaft speed, and shouldn't (theoretically) be impacted by gear ratio. I do know that the PSOM (speedo/odo module) is specific to gear ratio, however. I'd like to stick with the 3.31s, but if I found a good used 3.55 posi axle, I wouldn't turn it down.

I know it's a lot of questions, but I posted them all together, since they're related. Please advise.

Thanks,
Steve

 

In answer to your questions: You will not need to make any speedo corrections, as you are right about the rear end, if you get an axle with the speed sensor. HOWEVER, the 97-up axles will not work as the brackets are all different and not the same width. You are pretty much stuck with 92-96 8.8's without any modification.