Mike,
I have the exact same gearbox as chuckthetruck. I wish you lots of prayers and patience in finding one. They're pretty scarce as it, and the GM bolt pattern version seems even more rare.
Check Ebay often if you choose to go this route and be very patient. I ended up getting one off Ebay, shifter and all. And total costs for me for the tranny, shipping, a rebuild kit and labor for the rebuild has been under $400.
Check your local salvage yards too. If they have them, they'll probably sell for $150 and up.
-ftyler
