What spline axles are in the 11-up GT's
 

What the title says.

31 iirc

I'd be more worried about the axle tubes, pretty sure they're 31 spline though.

31 spline for sure.

31 spline axles with larger tubes then previous years. You have nothing to worry about Jeff.

Sweet. I guess I just need to worry about the tranny then. Ugh there's 3500 dollars.

I thought they didn't put the larger tubes until the '13 model year, was it just the 11's with that issue?

if your gonna launch hard, recommend getting your axle tubes welded. other than that, your fine.

6r80!!

The older models are 2.8'' and the newer cars come with 3.2'' tubes.

Also welding them up, you really need to jig the housing up to ensure it doesnt warp during welding.