borg-warner v-drive velvet drive

Greetings everyone, Yes, I see another thread with the same heading, but it doesn't seem to address the issue(s) I am experiencing, so here goes: I am a recent owner of a 1986 Century 300 Cortez Grande with twin 260 Hp Chevy 350's coupled to Borg-Warner 71c (as far as I can discern) Velvet...