what gear ratio?
 

i have a military m1028 dually, i was wondering if anyone knew what gear ratio the dually's came with, i have read that they had 4.88's in them, does anyone know before i pop the covers.

i know the pickups and blazers came with 4.56s but i dont know. do you have rpo codes anywhere on your truck

popped the covers, and they are 4.88's, i'm thinking of putting in some 3.73's because of the no overdrive issue. is this too high? i don't do any heavy pulling with it, just a driver.

no its not too high. the low end torque of the diesel gets you going fine and now with taller gears you can probaly do about 70 mph on the highway

thanks woody35, appreciate the info:U:

look out for some none electronic 4L80s on the internet and you could bump that up to 90 mph

my truck is 4 wheel drive, would the transfer case bolt onto the back or is there an adapter needed. and then would driveshaft length be an issue?

i forgot about the driveshaft but i bet you could find one that would bolt up to the 14 bolt. they made a lot of them. depends on what transfer case you got. they made turbo 400s till 1990 so the question is did they also change transfer cases in 1990. and if they did not they could probably fit a 4l80

i was thinking about going toe 4L80E route, a friend of mine gave me one with the torque converter, the problems being the driveshaft(possibly eliminate the front and just run one out the back) and being electronic it would require a stand alone ecu, but they are around a grand. i would love to put this tranny in, but i think i'm gonna go the cheap(gears) route for now. i would hate to lose the 4 wheel drive.

yeah the prices for those stand alone controllers are ridculous. oh and if you do go the 4L80 route make sure you got a diesel torque converter