Trans and T-case swap

[Brucifer79]

Hey everyone. I have a 79 Jimmy with the TH350/NP203 combo. I'm running about 3000-3500rpm's at hwy speed and I don't offroad much. I would like to swap to a 700R4/208 setup. 1: for weight, 2: the extra gear will help with hwy driving. I'm also considering a NP3500/4500 with a 208. What issues will I have regarding driveshafts, etc. The previous owner put warn hubs and a part time kit in but the 203 is growling like no other. Any help and advice would be great.

 

[nvrenuf]

What gear ratio and size tires do you have?

I ask because with a 31" tire you'd have to have 4.10's+ to run 3k rpm @ 65 mph.

 

[Brucifer79]

It has 31's on it now yes. The guy I bought it from said the previous owners put the 3" body lift on and had 36's at one time. I completely blanked on the gears! My tire plan is to put on either 33's or if I decide to change rims go with 295/70/17. The 295's actually add up to 34x11.5 which is a pretty good size for how the truck sits now.

Either way I want to swap out trans and t-case. I really want a manual trans but that's money and time I don't have right now.