Ok here is the story.

I lost 2nd gear at the track Friday night so I am asking for help on deciding which one to go with.

Car is a procharged 98 TA with 642rwhp and 558 rwtq at 14.80psi and a six speed. I track drive it 30 passes a year maybe. My best sixy so far is a 1.58 and best et is 10.87 at 131mph.

Thanks for the help, Mark

 

Well, Six Speeds warrantees their rebuilt transmissions to 700 hp, and just about everyone I've talked to says the stock T56 (in newish condition) can handle about that much hp. But if you want to play it safe, get the viper conversion/upgrade when you rebuild/buy another T56. I just replaced 2nd gear and my main input shaft on my T56. Just from typical wear of a DD. A rebuilt T56 with the viper kit upgrade from a good shop would be an excellent choice of transmission.