Branderino

Hey guys, I have some questions I was having trouble googling... Hopefully y'all can help me.

I have a 2004 V6. I swapped in a GT rear end out of a 99', guy told me it had 4.10's, but it didn't take long to realize the diff was worn out and it was still the stock ratio... Well I found some one selling the differential out of a 2004 Mach One (Not the whole rear end, just the pumpkin). How hard would it be to swap that pumpkin on to my axles?

Budget is really tight and i'm good with a wrench that's why i'm considering this, plus I have a REALLY strong desire to shorten the gears in my car (Mach One has 3.55 fyi)

dawson1112

Extremly involved swap,,, the 04 Mach1 uses independent rear suspension and the axles are different they use a half shaft type axle with CV joints. You'd need the entire rear not just the pumpkin. It would be much cheaper in the long run to just rebuild the rear end you have now with the gears you want.

Derf00

I'm pretty certain the MACH1 is is a Solid Rear Axle just like a regular Mustang. It just has 31 spline shafts instead of 28. The 31 spline is an upgrade for a regular GT so, if you just take the complete Axle it will swap into the GT easily.

The Cobra was the only one that had IRS for 03-04.

dawson1112

You could be correct, Maybe when he said the pumpkin only he meant its an empty case with no gears in it. As soon as he said pumpkin only I immediately went to IRS

Derf00

I gotcha, yeah I think of the Diff/pumpkin as a separate piece too but to be honest, I had to confirm my gut before I responded.

mustangman02232

99 and 01-04 cobras has IRS, i would just rebuild the GT rear, you already swapped one issue for another, why have another headache?

DBovine

Mach 1 is 28 spline stock, only difference between the two is the mach came with 3.55 gears and it was setup for larger rear rotors. So you can switch the differential from a mach 1 and install it into a GT housing just fine and still use the GT axels