I've seen a few posts on this, but I'm wondering for axles on an '80-'81 F100 are 31 spline like the F150s or 28 spline like the lighter car axles?

I want either Draglites or Torq Thrust II wheels, but the selection for the particular rims that I want is very limited for 5x5.5 bolt pattern. My truck is an '85 F150 shorty/flareside and if I can find an 80-81 F100 donor truck, I would like to switch the bolt patterns.

I'd have to swap the spindles, and all the brakes that go with it on the front and the backing plates and brakes on the back, correct? To me it doesn't seem like to big of a job, just replacing all the brakes that I did just 3 years ago Do I need to swap I beams as well?

I'll probably take alot of flack for going smaller, but it's not a work truck anymore. Retired as a street rod with no trailer hitch. Any help is greatly appreciated! Thanks in advance.

 

You won't take a lot of flack from US for going smaller. It's your truck, so you're free to do with it what you want.

BUT... and I can't emphasize this enough, I'm pretty sure in all 50 states it's illegal to downgrade to a smaller braking system. So while you could put the 5x4.5 axles in the rear and convert the front, it would be pretty pointless to do that because:

1) The brakes in your current truck are brand new-ish.

2) You can find just about any style rim you want that will fit a 5x5.5 bolt pattern (Dodge, Ford, Jeep all share this pattern).

3) The brake system on your truck is already there, no need to swap anything. It's easier to change rims than it is to change axles AND rims. And, your current brakes are better (even if marginally) than an F100's brakes.

You can find some Draglite styled wheels online pretty easily.

What size tires do you run? You can fit a 10.5'' wide tire on a 7 or 8'' rim with no problems and they'll be just fine. On a 4x4 truck they might rub with that kind of rim on the front. You have to look at backspacing and stuff.

Here's some that I think would look good on ANY 80 to 86 pickup:

Ford F150 American Racing Wheels at Andy's Auto Sport

Ford F150 American Racing Wheels at Andy's Auto Sport

Ford F150 American Racing Wheels at Andy's Auto Sport

Here's the list of rims they have:

Ford F150 Wheels and Rims at Andy's Auto Sport

 

Why not buy these? It would be easier, and should be safe for a street cruiser. You could order your wheels with a little bit more backspace to compensate for the thickness of the adapters.
4 pcs | 5x5.5 to 5x4.5| Wheel Adapters | Spacers | Billet | 1.5" | 12x1.5 | eBay

 

The '80 and '81 F-100s with the 5x4.5 pattern are basically car axles, just with the truck mounts. They use a standard roller bearing (not like the tapered in the others) and the seals are pressed into the tubes. They will be 31 spline.

 

Like Dave said....I think the only difference in the axles is the bolt pattern. Should be the same splines.

 

Cool, I'd never thought of adapters. That could be another option as well. I'm in Canada so and I'm not sure what the laws are on the braking systems but I didn't know the F100s brakes were actually smaller brakes for some reason I was thinking they were just a different design. Going smaller is definately out of the question for me seeing as the truck is quicker than stock.

Ford F150 American Racing Wheels at Andy's Auto Sport

Those are the ones I want! Guess I just wasn't looking hard enough. Tires I have now are 255/70R15s all the way around. I like how they fill the wheel wells. I'd like to get the absolute widest I can on the back.

Looking into dream beams now, wheels will likely be after that. Thinking 2" drop front and back. I'll search the forum for existing threads on the dream beams as I'm sure there are already some on here. Sorry for the long post, thanks alot for your input everyone.

 

I don't have the link as I'm on my phone, but if you look for a recent thread on f100 camper towing all the information on your brakes is in that thread. There is recent activity in the thread so should be easy to find. Not all the brakes on the F100's were the same

 

I have a 80 F100 with the 4.5 wheel spacing. The front brakes are smaller with
a power booster and the I-beams have kingpins. The rear axle is a 28 spline 9 inch.
I know because I've replaced the bearings on both sides.