Cougar XR7 - 3.73 Gears

Stock, my Cougar came with a 3.08, open differential rear end. Ford never should have put 3.08 rears behind a 4000lb car - I don't know what they were thinking!?! To overcome this, I ordered an aluminum 3.73 Trak Lok pumpkin, from JustinH - another user on It is complete, and the install is something I can do myself - whereas replacing the ring and pinion in the stock unit would require tools I don't have, and work would feel comfortable doing.

Ready to be installed

The gears are in, and the install was pretty straight forward. I neglected to take photos (I knew I would be filthy, so I didn't bring the camera)... All in all, it took about 6 hours, with several "beverage breaks" along the way :)

Now that I have clocked a few miles on them, I felt it only appropriate to open 'er up, and see what the car feels like... It's MUCH stronger. I knew it would be substantial, just with the way it felt during very easy driving. you could feel that less gas pedal was required, to get the car on her way. The gears get this heavy-ass car going, much better.

As measured by a G-Tech Pro, my 0 - 60 has been reduced by almost a full half second (comparison methodology require a minimum of four runs - two each direction - then averaged). Not too shabby! I haven't been able to measure any difference in gas consumption, as yet. I will complete this update after I have gone through several tanks, to accurately measure any difference at all.

Prior to selling the Cougar, I wasn't able to obtain additional empirical data, to quantify the improvements made by the gears. There was a definite SOTP increase, and I thought it was well worth it.