Can anyone tell me if you need to lower the transfer case with a six inch lift? Id like do know if you have to on a 1976 chevy and a 94 ford f150? If you dont need to drop it on a six inch lift then what size lift would you have to do it?  

Automatic or manual? I had a 76 Blazer with a custom 8" (Started as a six, but I did a Shackle reverse on the rear with 3" blocks and six inch springs with longer rear shackles on the front) and a manual trans and had no problems with binding or losing stock shafts. As far as the Ford, don't know. Don't play with them enough.

The chevy is a 4 speed and the ford is a automatic.