I recently got a 78 K5 Blazer with a 203 full-time 4WD transfer case - but it also has free wheeling hubs. So, I assume it's had a full-time to part-time kit put into at some time. I know nothing about these transfercases either way. I've got twenty 4WD trucks, but they are all part-time 4WD - and my GMs are all 205s, 208s, or 241s - except this one. So, I'm trying to figure out what the different positions are - and would they have changed if a conversion kit was put in? I know it used to have a full time 4WD position, a locked 4WD positon, low-range, etc. It seems right now, that if I push it all the way forward it feels like it's in 4WD low -but I haven't tried in the dirt or snow yet - I'm in the process of putting a plow on it.