first let me say that i spent a few days checking out all the replies on posts and i was genuinely impressed with the answers supplied. my question is i have a 89 jimmy full size and i have just put a new 350 in it with new hooker headers and exhaust, it has a th350 in it, not sure how to id the transfer case yet(help with that would be appreciated) the label in the glovebox says the differential code is GU2 which means that i have 2.73 gears and i plan to use this jimmy as a daily driver and some rock climbing and these gears aren't going to cut it for me, i am running 35x12.5 tires, what gear ratios would u suggest? thanks for your input

 

at a minimum go with 3.73 but 4.10 or 4.56 would be better, if your just looking at changing the gear ratio and not do an upgrade to 3/4 or 1t axles you can find 3.73 10 bolts at the junk yard for cheep

 

thanks for the help i got lucky and found a dana 44 1/2 ton front and a gm 12 bolt rear with 4.10 gears for 300 on craigslist, now im looking for a 700r. can u tell me how i can identify which transfer case i have? thanks

 

2.73! OUCH. Those 4.10's will be a word of difference and at only $300, that is a pretty good deal!