Pulled a of a 73 jeep cj, it says muncie t10(its a 3spd) to an advanced adapter?

all i can see is it says T10 muncie (its a 3 speed) to an advanced adapter (jeep adapter) to a dana 20 (i believe) transfercase. has anyone ever seen such a deal? or can anyone tell me alittle about the ? ive never heard of it