need a balanced ls1 DS with new u joints....

 

I don't think the LS1 aluminum driveshaft is going to stand up to your power level. Do a search on the Drivetrain section for the strength of the LS1 and 1LE driveshafts. If you would like a stong aluminum driveshaft, I have a Lingenfelter 3.5" aluminum driveshaft for sale on ebay, item #7922841880. It's worked great in car car with 580 rwhp; I swapped rears so I going with a shortened driveshaft.