dunno the answer to your question. When I bought my T18, I just put it in first, rotated the input shaft over 6 times to get the output once around...knew that was the 6.xx:1 granny low version.
Novak ofcourse has a lot of info,but it still sounds like a lot of hit and miss.One source says mainly 77'-79' and look for T-18 a or 1301 but I think this just indicates Jeep. I would say Renegade T has the surefire answer if possible. Call Novak and maybe you could give us an answer.