I'm starting the preliminary planning for my next project, a 1976 F-100 RWD LWB. I've followed several of the Crown Vic swaps detailed in these forums and that's firmly on the list of mods. This will change the bolt pattern from 5 X 5.5" to 5 X 4.5 " and the size of the CV disc brakes will require 16-20" wheels with c. 5.25" back spacing. I'd like the wheels to match in appearance front to back.
The question is what to do about the rear axle. Options seem to be limited due to the outside width of the stock rear axle (65"). So the popular choices seem to be the following three:
1) Retain the stock 9" rear, modifying or replacing the axles to obtain a 5 X 4.5" bolt pattern and converting the stock drums to disc brakes. Adding a rebuilt center section with pos-traction is a nice extra.
2) Swap in a '95 or newer 59.5" 8.8" Explorer rear axle. Lots of plusses here such as 31 spline axles, pos-traction, etc.
3) Use the '03 or newer CV rear which is also an 8.8 but considerably wider (67") than the Explorer.
The Explorer option looks better to from a cost/benefit perspective but I may not be considering all of the relevant variables and I may even be overlooking other viable options.
So what are your thoughts on the matter?

 

An additional option is to install an early 80s half-ton 9-inch axle already equipped with the 5x4.5 pattern. Bolt in and go. They are out there.. the challenge is finding one.

 

1980-1983 F100 9inch rear end that has the 5-on-4.5" lug pattern.

 

... and there it is.

I'll start perusing the yards and stock them.

 

That's a new one on me .... but then there's this thead:

https://www.ford-trucks.com/forums/9...1982-f100.html



To "OP" ..... why mot a 98 up 8.8 from a CV /MGM .... since you are already considering a 8.8?
Slightly narrower letting you run slightly deeper offset rear wheels?

 

Explorer 8.8" rear ends prior to 1995 have drum brakes. '95-2001 will have discs.

Not all Explorer rear ends have a Traction-Lok differential (it was optional).

There were several ratios available but most common are 3.55, 3.73 and 4.10.

I have a '96 model Explorer 8.8" rear end. It has 3.55 gears but it doesn't have a Traction-Lok differential.

 

I know where an '82 and an '83 F100 are. ....Both have the integral rear end though.

 

Thanks for this good info. Do any of these have disc brakes or, if not, are there conversion kits that aren't awfully expensive?

 

The 80s axles cited above are all drums.

TSM Manufacturing has low-buck conversions. I recall Scarebird Brakes LLC has some too.

 

The '80-'83 F100s (not F150s) with the 9-inch rear and 5 x 4.5" lug pattern have 31-spline axles and the same (wider) housing width as the Dentside 9-inch rear ends.

The '80-'83 F100 rears with the smaller lug pattern have smaller drum brake assemblies than the truck 9-inch rears with the larger 5.5" lug pattern.

It is possible to install '94-'04 Cobra Mustang 11.65" ventilated rear discs and calipers onto the housing with conversion brackets available from Curries.

Complete setup.

Currie Enterprises Racing Rear End Categories


Brackets only.

Currie Enterprises Racing Rear End Categories

 

I'm still undecided on axle. I have an explorer 8.8 but it seems way too narrow. the leaf springs are basically right beside the backing plates and I will need some pretty massive offset wheels to fit.

 

There was a fellow on here who did the Crown Vic swap and used the 02 and earlier Crown Vic rear axle as it is a bit narrower than the 03 up but wider than the Explorer axle, worked great with the Mustang Cobra rims he used. Look for a thread with a rusty/patina green 73.........
At this point I'm planning on using the 03 CV axle in mine, but haven't done any measuring or fitup yet...

 

Found lots of other nice bits of info on the CV IFS swap itself but couldn't dig this one up. It seems that most folks keep the 9" unit and work from there using disc brake conversions, swapping axels and re-doing the center section (pos-traction) at considerable expense.
There is a need for an affordable solution that is compatible with the CV IFS that doesn't require spacers or unusually offset wheels.

 

Here are the numbers that I've seen quoted here and in other forums:

Crown Vic 2003 + = 65.6"

Crown Vic 1982-2002 = 62.8” wide

F-100/150 9" 1972-1979 = 61.25”

Explorer 8.8" = 59.5"

There are a number of threads about narrowing the Explorer rear end by replacing the 'long side' tube and axel with a 'short side' tube and axel. This makes it 3" narrower.
So what if we reverse this thinking by replacing the 'short side' tube and axel with the 'long side' tube and axel? That would widen it by 3" making it 62.5" wide which is only 1.25" wider than the stock 9" rear end. Apparently these tubes are not welded in.
Of course spring perches would have to be welded on after the pinion angle was calculated but that wouldn't be a problem for most here. The offset of the pinion would be changed of course but would that be a problem? How would this compare to the placement of the pinion yoke of the stock 9" rear?
In short, does widening the Explorer rear end seem feasible?

The pre '03 Crown Vic rear looks like a good option.

 

Here's the one I was thinking of.
https://www.ford-trucks.com/forums/1...-vic-swap.html