I bought a 2002 2500 HD 4x4 Crew cab 6.0 4 speed auto.  I was windering if there is a code that would tell my ratio of if someone could use my info to help.  @65mph i am running around 2250rpm in overdrive with a 4l80e tranny. and my tires are 265/75/16.  any info would be helpful  

You likely have a 4.10 axle ratio,it is a GT5 code on option code list in glovebox.  

ive also seem the GT4 code of 373 on those trucks too...pretty much the only two options of gear ratios for K2500HD and k3500.  

Neither one is good for oversized tires in that truck with OD tranny, especailly the GT4.  

it does have the GT5 code.  thank you for all your help  

Up thru 2000 on OBS truck (Old Body Style) they used to have a HC4 option (4.56). Also, up until 88 they had a HF8 (4.88) and a HC7 (5.13) option too on 1 tons. The silly part is that they had great gears before there was OD trannies and then when they had OD trannies (which would have played really well with OD trannies) they did away with the deep gears. They killed HC4 when Dmax came to market because they did not want you to have option of gearing a gas truck to be a stump puller because they wanted to sell you a Dmax instead. Even a 6.0 would have towed quite well with 4.56's. A 8.1 with a allison and a 4.56 would have been a real tow beast that could have shamed a Dmax.  

i was unfortunate to get the 3.42 ratio on my 14B FF. its got 4.56 yukons now

wouldnt go over a 33 with just a 4.10  

Hey snoman, been reading for a while and just joined today, but it sounds like you know gears beter than anyone i know, so what is your opinion for gear ratio for a v10 burb with 33's and a basicly stock 350? Friends are telling me 410's but from what ive read im not sure thats enough, dont want to hurt my 700r4  

NoTime:
Hey snoman, been reading for a while and just joined today, but it sounds like you know gears beter than anyone i know, so what is your opinion for gear ratio for a v10 burb with 33's and a basicly stock 350? Friends are telling me 410's but from what ive read im not sure thats enough, dont want to hurt my 700r4

Having owned a 89 4x4 burb since it was new and still do, I kinda know it a lot better than most. Your "friends" are not quite on target here. A burb is a heavy beast and it needs some deep gearing to make it move effectively and with minimal transmission strain with big rubber. Figure on 4.10's for 31's and 4.56 for 33's and 4.88 for 35's. Do not let numbers scare you with deeper ratios because the 700R4 has a .7 to 1 OD ratio which means even with a 4.56 and 33's, your RPM at a 65 MPH cruise is about 2100 which is about just right for a best power and economy. Also I might add that regardless of axle ratio and tire combo, burb due their best on MPG at 65 MPH and less cruise speed. MPG can start taking a big hit above that and really drop at 75 and more.(especially with a lift and bigger tires) My 89 is stock and it has over 180K miles on it and with Mich load range "C" 235x75/15 running close to 50 PSI and 3.73 gears if I keep it under 65 it will do better than 18 on highway all day long using A/C and if you keep it under 60 it will crack 19 MPG. (I had run 31's on it for many years in past but found 3.73's lacking in OD and went back to stock tire sizes 8 years ago) I might add that the 350 TBI responds and wakes up if you set timing from TDC to about 8 BTDC and use 89 octane or better fuel. You will feel the difference right away and MPG will pickup too.  

Thank you, thats exactly as i figured. I bought this 88 Sub for 800 bucks, the body is a little ruff, not bad, no rust, but other than that it is perfect, inside too! Basicly i needed a vehicle that could haul my wife, new baby and 3 pit bulls in, and i came across this burb by accedent really. my wife was on me one day about getting a bigger vehicle than my bagged 87 s-10, so jokingly i asked a friend if he had a large truck  for sale, and he said he had a burb that he needed to get out of his mommys yard, lol. he got it from a guy who died but it need a computer and some other small stuff, he couldnt afford to fix it so, wahla! Anyway i love this beast! Thanx for the input.  -Dan  

thats the opposite of me...got together w/my wife and i had an 86 sub and i loved it, had fun muddin, climbing hillsides, waterholes, you name it and i tried it w/the sub...my wife hated it said it was too big,so like a dumass i got rid of it...now i have another kid an two dogs and 1 single cab 93 k1500 to haul a wife, 2 kids, and 2 dogs....schit!  

Burbs do grow on you. They are the Cadillac of the 4x4 world and in a league of their own.