I found the part number for you. It's B&M part number 80742. I'm about 99% positive, so if you're ordering, check before you finalize.

 

In this months GM High-Tech under the "best of SEMA"
They have a sidewinder Shifter Ball? With this link

www.mrgasket.com/fp99.html

But if you look under the Hurst shifter section you'll find what your looking for. I think it come's with or without a 12v botton for nitrous or what not.

Edit: these are made for the T-56 Tranny. With the GM 16MM x 1.50 Thread pattern

 

thank you for your help lion