Put deposit down on a '17 last week : ) I would like to replace the stock 3.73's with a 4.56 gear set---will work much better for my non-track use of the GT's rpm range---would allow two red-line shifts on the way to 100 mph vs only one for the stock gear set, still cruise at 80 mph at 2800 rpm in 6th---just think it would make for a better street setup. (Please give feedback if you deem a bad idea)
Ford Performance does not offer a 4.56 set for the IRS, and no web search turns up a set. Does anyone know of a supplier? just a matter of time? thanks! Jack
Jack, you and I are of the same mind on this subject.
The Ford Performance Dept of Ford has a 4.09
gear set. They can be ordered and installed by your local Ford Dealer ship
Here are a few questions that will arise with a gear swap.
1) The GT-350 has differential lube cooler in conjunction with an outside radiator.
2) Ford engineers jumped through hoops to hide the vibration and cabin noise that is inherent with the Flat-Plane-Crank in the engine (affectionately known as the VooDoo engine). Changing the gear set might interfere the delicate balance of the engine drone and resonance.
3) Maybe the gearset will possibly interfere with the differential cooling system
Jack, besides my GT-350, I have a Street/Strip racer which has had two 4.10's (stock GM both broke). One set of 4.11's in a Moser 9-inch detroit locker. I now have 4.56's in the moser. The car is now a perfect toy.
I posted here, because I wanted to know if anyone has yet made that gear swap and if there were any issues.