Help, I think

After wading a few drive shafts up i need to know how to figure my critical speed or some thing of that sort so I can have my carbon fiber one made. (4L80E), 4.10's, 29.67" tire, my flat to flat measurement is 56.125". Ok, now on to what i have thrown out 3.5" .090 wall DOM steel shaft, 3" chromolly .065 wall, 4" .120 wall aluminum one so i guess what im asking does any body know what my critical speed is or what else is needed to help me fix this isshue? Dont really want to spend $850 on a carbon one if i can make do with some thing else.

Just call Denny's Driveshafts and give them all the information and they will tell you what works best for your application and can build it for you with quality materials.

Call Austin Drivetrain. They do awesome work and can help you out. :thumb: