97/98 Mark 8s had the most powerful single fan Ford ever made moving some 4500 CFM. A great upgrade if your cooling is needing a boost. Although in 2010 Ford finally made a more powerful factory fan for the F150s but it’s so thick there’s no way you could possible put it in the Mustangs.

On the left is the stock 03/04 Cobra fan. On the right is the Mark 8 fan. Notice it has a shroud too which helps even more with cooling.

You’ll have to take a notch out of the Mark 8 fan just like this picture to clear the ABS unit.

The Mark 8 fan fits perfectly. Almost like it was made for the Cobra. If you have a stock intercooler reservoir tank you’re all set. If you have a larger oversized aftermarket one like I was running at the time it’ll need some notching.

Here you can see how well it fits at the bottom too.

Here’s the notch I made at the top passenger’s side for the oversized intercooler tank I mentioned earlier.

Here the fan is back in place and the OEM radiator reservoir is back in place. You can see the notch for the intercooler reservoir.

The intercooler reservoir in place closing up the gap of that notch I made.

Here’s a simple jumper harness I made to plug the Mark 8 fan directly into my Cobra’s harness like it was made for it. When you grab a Mark 8 fan from the junk yard be sure and grab the wiring pigtail with connector as well if you want to build one yourself.

Once it’s all back in you can’t even tell except the fan moves a tremendous amount of air and cools the motor down very noticeably quicker than the stock fan can.