4x4 Conversion
http://en.wikipedia.org/wiki/New_Venture_Gear
Manual
NP208
NP231 (S10 Blazer) http://www.jeepforum.com/wiki/index.php/NP231
NP241 http://www.jeepforum.com/wiki/index.php/NP241
NP241OR http://www.jeepforum.com/wiki/index.php/NP241OR
NP242 Jeep Selec Trac FT4/AWD http://www.jeepforum.com/wiki/index.php/NP242
Electric
NP233
NP236 Computer AWD / RPO NP8 AutoTrac (S10 / Blazer)
NP243
NP246 Computer AWD AutoTrac (Suburban / Tahoe / Yukon)
NP249 FT4/AWD http://www.jeepforum.com/wiki/index.php/NP249
Possible Clocking Ring sources