my friend blew his 6-speed for the second time and wants a more heavy duty one. where and how much is one? one guy told him 1100 to rebuild.

 

D&D Performance (http://www.ddperformance.com/).

 

they seem to only have stock trannys , he needs a stronger one..

 

They actually rebuild T-56 to make them stronger. I know they do a conversion to get an Viper output shaft in an LT1-T56. They also can upgrade your 2 to 3rd shift fork. I think there is a place in Indy that cyros to make the internals of your tranny stronger.