So i'm going to be getting either an 03 or an 04 cobra, plans are blower pulley and gears, either 3.55-4.10s. Was just wondering if the stock rear end would hold up with slicks on the track using those gears. Pulley will probably be a 3.10'' pulley, I wanna keep it fairly stock.
Met a guy the other day who broke a half shaft on his first launch with Nitto DR's after CAI and pulley. Don't know what size pulley he was running though.
So I'd say no, stock IRS won't hold up with all that. Probably won't hold up to slicks for long even with just the stock motor.
I know the half-shafts are pretty weak once you add sticky tires and more power. Look at it this way, some thing has to give on launch: clutch,trans, rearend or tires.
Adding slicks eliminates the tires and stock trans is pretty strong. Therefore, something else is going to slip a little bit and the rear won't slip, it'll break.
Also, the car comes with 3.55's and i would tend to leave those alone. Once you start adding more power, you won't need anymore gear.
The 03/04 Cobra's come with 3:55's stock and there's really no reason to drop to 4:10's. The car makes plenty of power and runs out of gear pretty quick as it is.
The stock rear end in stock trim won't hold up to slicks and high-RPM clutch dumps for very long. Eventually you'll snap a half-shaft or you'll grenade the differential cover from the torque.