[dukeofdexter]

Any reccomendations for which gear box to put in my '97 Cougar? Ive heard '03 bolts right on but I may be misremembering.. Any modifications required or should I just put gears in my OEM gear box??

Stage 2 cams will be ordered soon and very likely a torque converter to go along with..
Im thinkin 2600 stall and 3:73's from an '03 cobra, just doin research tbh

 

[Rodeo Joe]

Talking about the rear differential right?

The 99 Cobra is the only one that bolts right in because it has the 28 spline axles like our cars.

Joe

 

[dukeofdexter]

Thanks for the tip, I did mean differential not tranny.

Would it make more sense to just put gears in the og diff? Or would be plug and play with the '99?

 

[RalphP]

I'd put gears into the original diff; or build up a Mark VIII diff, your choice.

Or build up a boneyard MN12 diff; same diff. *grins* Well, the Mark VIII will be aluminum housing.

RwP

 

[dukeofdexter]

Ill keep this in mind, lookin at this project towards the end of summer maybe

 

[krewat]

When I did my '96 t-bird 3.73's, I found a low-mileage cougar diff (same diff) at a local junkyard, and built it up with an Auburn LS and 3.73 gears, and then swapped when it was all complete.

If you can have your car down for as long as it'll take to swap the gears and do it "right", you could redo your existing diff. At the time, I couldn't take the downtime. And I actually still have the original diff under my bench

Actually, I think I still have the Ford LS that was in the Cougar diff, complete with side-gears.

I'm getting old

 

[Philippe Mentor]

Here's my two cents. I have done the gear swap plus the very hard to find TracLoc diff carrier. I paid a lot for labor, and it took like three weeks but I wasn't in a hurry. It costed more because I wanted to use genuine Ford parts. Sourced the diff from the guys at TBSC on the net. Unfortunately once taken apart found parts to be not in good condition. So we replaced all parts with Motorcraft. I could have gone with a pre-assembled Auburn diff from Randy's Ring and Gear for far less and bought the new gear set and get it dialed in by a shop For less than I paid would be my suggestion.
If anyone is interested in a 3:27 ring and pinion, name you price.

 

[Philippe Mentor]

Oh yeah, don't forget to buy a new 21 tooth Speedo gear and retainer clip for the 4R70W automatic. Buy Motorcraft!

 

[muhfreedom1776]

I've seen a 28-spline TL diff for sale on super coupe performance, going for around $400. Anyone know anything about that? Says it's supposed to be a direct replacement for the coog/tb IRS diff.

 

[T6Rocket]

The SCP unit is not a Ford unit, I think it's Yukon. It will work, but will need all the clearances checked once installed. Which most people do anyway.

The Ford unit is a direct drop-in, but it is a crap shoot whether you're getting the newer IRS compatible one or the solid axle one, since the part # is the same. It took me two tries to get an IRS one.

Al