I have a question regarding E150 and F150 / Bronco 8.8" rear axle interchangability.
First this is for my 1988 E150 Van with a 351 EFI / C6 combo. Currently according to the axle code it has a 3.08 ratio. I would like to drop down to the 3.55 or 3.73 area as this thing is a dog towing.
And that is saying something as my little C600 at 22k only has a little 330 V-8!
So if I look around, if I find a rear axle out of a F150 that is a 8.8" will it bolt up? IE spring perches and such.
I know that Ford was not to keen on the 3.73 gears, so would it just be better to spend the money and have a set of 3.73 gears put in my current axle?
Van axles have unique width, perches, and brake setup. My interchange catalog (for salvage yards) shows 1987-91 e150 vans as your interchangeable parts/years. You would be better served swapping out the gearset.
As far as I know, we can swap in anything from any 31 spline ford 8.8 inch axle with a 7/8ths crosspin, except axle shafts. I fitted my 95 E150 with an Eaton electronic locker they advertise as being for F150s and Broncos. ABS gave me some trouble until i found contamination on the tone ring. Axle shafts from 87-96 e150 vans are apparently the same (per my interchange catalog.) The cost of new internals is so low, its not worth having used internals. I am contemplating a 3.73 gearset, new they only cost 130-200 bucks, and a full rebuild kit for the 8.8 is only 80 bucks or so more. I recommend reading the guides available on 8.8s before you try, as certain parts of the task (pinion preload and shimming) are not easy.
The van axles are the widest version of the ford 8.8.
i once swapped a 9" from an 80 e150 into an 86 F150 that came with an 8.8, and that was a direct bolt up.
i'm not aware of any changed in the suspension and axles between the early 80s and late 80s, so i would expect it to fit. take a look around the junkyard with a tape measure in your hand, it might fit, it might not. but i've seen plenty of "impossible" things work
but as you mentioned in the first post, 3.73s weren't very common, so the time/effort of finding one might outweigh the cost of just rebuilding yours to the gears you want