Help with 5-Lug Swap and upgrading to 31-spline axles

[racerxmd]

Recently bought a '85 T-TOP GT w/5-speed trans. I am wanting to do a 5-lug swap but have some concerns and which parts to get. I am installing the Wilwood disc brakes all around. Front swap us easy but what about the rear? Which posi-traction unit to choose for 31-spline? What about axle lenghts? Car will be a mostly Street car with acasional trips to the track.

Thanks

[Lowetlx]

https://lmr.com/item/M4204F318C/Must...SABEgIIe_D_BwE

03 cobra rear diff, Have seen it go for $199 on eBay or from lmr with a coupon code

[vdubn]

A lot depends on what your plans are in terms of wheels, and if the Wilwood brakes will work with different axle length options. I have an 85 T Top GT as well, and I also am just looking to build a fun weekend car with occasional trips to the track. I opted for a std 8.8 with 28 splines, which for general use is plenty strong. Most guys that step up to the 31 spline axles and diff, are looking to do some hard launches at the drag strip, and plan on getting lots of grip (like with slicks, etc.). For most any street tire, you'll break the tire loose before you'll give an 8.8 with 28 splines any grief. Not saying that they can't be broken, but you would have to really hook up, and launch really hard.

All that said, I decided to run Cobra brakes all around, so I chose the guys at NorthRaceCars, because they had a nice setup that included axles specifically for our cars running SN95 (Cobra) brakes, and still keeps the stock Fox Body rear track width (which goes back to why I said that your wheel choice comes into play). If you don't plan to run 9.5 or 10" rear wheels, then running a wider SN95 axle may actually be fine.

I don't know if NorthRaceCars sells 31 spline axles, as all I have seen listed are 28, but its probably worth a call to see if they can get you some.

Make sure the Wilwood setup has everything you need to connect your parking brake. I ultimately chose to stick with the stock parts due to cost, as the Baer and Wilwood stuff gets pretty spendy, and depending on your axle-width-to-axle-housing configuration, may require some additional parts to get mounted correctly.

Good luck with the project, sounds fun.... post a pic of it

[cb84capri]

I have a 31 spline Ford Explorer trac-lok diff in mine with the standard clutches stacked the modified way, with stock length 5 lug Moser axles.

Cale

[erratic50]

I really dislike SN95 rear diff and rims/tires all from a 95 GT that's under mine. In building a fox width rearend with northern racing brackets and sn95 brakes.