FastDEW

I did exchange emails with Shaftmasters prior to ordering my 4 inch driveline from them. They told me that it would not contact anything even if I lowered by 1.5 inches. They said the 2010 is different somehow from the 09-05 in the floor pan which allows for some extra clearance with the 4 inch shaft on the 2010. Further, they told me if I had any problems at all, I could return for a full refund, no problem.

Lastly, I did ask about shaft RPM and maximum speed. They said it would be good for more than the 149 MPH top speed limit on the stock 2010 GT. I didn't ask how much more it would go because I won't be going that fast anyway.

Now I just need the car

Cusp

Since the drive shaft sits between the transmission and rear end, its RPM is dependent on the wheel linear velocity, the wheel circumference, and the rear gear ratio but not the engine RPM. Well maybe in 4th at a 1:1 gear box ratio. That said, changing the rear gears from say 3.31s to 4.10s will increase the Shaft RPM by about 24% for a given speed over the ground. Most likely your safe at 120MPH. I just thought I would mention it in case you wanted to check. When I did it, I made sure my shaft and its critical rpm would not be exceeded in excess of the cars top speed limit. Not engine red line but when its power would be maxed out pushing the air out of the way plus a safety margin. In my case, I calculated I would have to be going 193 MPH. Test show that my car configured as it is tops out power wise at about 150ish. Hopefully that is enough.

atomicpunk

Just installed a PowerHouse 4" driveshaft last weekend and I'm lowered with the FRPP handling pack. No clearance issues at all under the car including the parking brake cable.

eddypython

so which one should be better the one with the pinion flange or adapter plate ? that's 50 % chinese to me. lol

atomicpunk

Driveshaft with an adapter plate is less of a hassle to install, don't have to mess with the rear pinion nut torque.

JimsGT

Highly Recommended:

http://www.axle-exchange.com/

Also, Sydershaft makes the shafts for Steeda