Two questions here.

I have a line on a FRPP Pumpkin that is for an IRS Cobra, or IRS Tbird with 28 spline gears.

It is a 3.73 with trac loc and aluminum housing.

What does my 98 f150 accept, I thought they had 28 spline gears, but I know they have the solid axle, so can I make the IRS unit work?

My truck has 3.73 open, and I really would like the trac loc function.

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Ok, here's my second question.

I have the 99 lightning brakes in the front, and I want to go to discs in the rear. Is there a how to, or list of parts.

Thanks,
JH

 

What is the axel code on your door frame?

I believe that most/some 4.6's came with 8.8's rear ends, which also was a very common rearend in rangers, and some mustangs.

I'm pretty sure that there are some 4.6's, and most 5.4's, with 9.75'' rears, not too many vehicles that I know of that use this rear other than the F-150's and Expy's.

If your f-150 does have the 8.8" rear, I'm pretty sure that you could use the Trak-Lok in the truck. It would still depend on wether it's 28 or 31 spline though....I think that most newer vehicles use the 28.

If you have the 9.75 rear, you can find some good ls units on ebay for super cheap.

here's an example of a used 9.75 LS unit on ebay.
http://cgi.ebay.com/ebaymotors/ws/eB...tem=2466697016

I think that your best bet would be to swap in a axel off a newer wrecked F-150 or Expy with the LS unit in it and all ready to go with discs, and calipers and the proper gears.

http://cgi.ebay.com/ebaymotors/ws/eB...tem=2467504925

You could pick up the disks and calipers halfways cheap, but the parking brake linkage may be another story for this particular item.

More than one way to skin this cat...

 

Thanks, I'll check around ebay.

My truck is the nascar edition, it has an 8.8 rear with 3.73 gears, open.

The truck isn't nearby, so I don't have the axle code right now, but I looked it up before and thats what it told me.

Thanks,
JH

 

I dunno if you saw my edit, but I did find a nice rear axle that may swap right in....

I'm not sure if the 8.8 has the capability to convert to disks, but I'm prolly wrong on that.

I think that there were some explorers that had disk rears, before they redesigned the explorer, you may be able to rob the necessary hardware from one of these.

 

I would think that a truck would have 31 spline axles, but I could be mistaken.
If you have 28 spline axles, then the posi unit from the IRS center section will work in your housing.

 

Yup these trucks have 31 spline axles.
The easiest way to do the swap would be to find a complete rear end with the limited slip and discs. I would think that it shouldn't be too hard to find. If you could find a complete rear end, including park brake cables etc. that would be an easy swap.