In Iraq with the Marines, and buying up parts. Question is: got stock gears in a 10 bolt front and 12 bolt rear. tire size is 33", but just got 38" which are going on. where do I need to go to run these about stock setup, and where would i go for even more aggressive approach. I was originally thinking 4:10, but now after reading some of these posts I am thinkin 3:73. Going to be doing mild to hard off roading, but would like to drive occasionally on the road. Thick gears? Runnin fresh 350 out of the box. 350th tranny, 208 TC. Just lookin for some advice from some experienced wheelers. Tried lookin for a chart, but from the sandbox resources are limited, and a chart can't give an opinion. Anything is appreciated.

you will need more like 4.56 or better.

3.73 or even 4.10 will be way too high (numerically low) to do anything useful with 38 inch tires, especially if you are using a big heavy tire such as a swamper or the like. I have the same setup as you are planing, besides the t-case. I'm running 4.10's and 38.5's and, besides use in mud or sand it's rather useless. this is the reason I have plans to go to a dual t-case and 5.13's. I would say that if you are going to use it on 1/2 tons you might do yourself better to stick with 4.10 to 4.56 if you can get away with it to reduce the torque you are trasnmitting to the axles, maybe they won't break, maybe they will. if you are planning on doing anything going slow such as rocks or trails with technical uphills, lower will be better but you will need to keep a short lease on your right foot to save the axles.

-Scott

Heck, I'd be looking to replace at least the rear diff, if not the front.

Too much tire, too little beef.

with 4.10s in my 44/60 i broke more shafts (front and rear) than i can count on 2 hands. now i have 5.86s and a 60/70 and havent broke a thing. find a 14 bolt with 4.56s and regear your front and u will be ok. just carry some spare front shafts.

Thanks for the quick responses. What would be a good match for the rear 12 bolt if I chose a front axle swap?

dana 60 front and 14bolt or dana 70 rear is the hot setup. not too big not too small. if you go with the dana 70 rear you have lower gearing choices. those of use that have 14's are stuck with 5.13's as our lowest option.

-Scott

For 38's you can keep the 12 bolt by trussing the housing and putting in cromo shafts. I wouldn't go lower than 4.56 in a 12 bolt since the pinion gets kind a small around there. 14ff are cheap, but they catch the newpaper on the way out of the driveway.

i was running close to what your planing on runing, you have to be honest with yourself is this going to be adaily driver or a nardcore off road rig. If your going drive it on the road mostly i wouldnt change axles and prolly go 4:10 or 4:56, mine had 3:73 and with a healty V8 youll do fine on the road but you will losse power going up hills. if your going for hard core off road youll have to change axles and go with at least 5:13 gears check out roughcountry.com they have a good gear chart that will break it down for u, this is just my 2 cents hope this helps you out. stay safe over there

4.56 with at least a 44 up front over the 10 bolt. I have an 87 blazer that is about to receive 60's front and rear.


Chris

4.56 with at least a 44 up front over the 10 bolt. I have an 87 blazer that is about to receive 60's front and rear.


Chris

A Dana 44 and a 10 bolt are essentially the same as far a strength goes. For 38"s, in a DD (read: you'll be easy on it because you have to drive it on Monday) a D44/10 bolt with some quality shafts and u-joints should be fine. To keep the rear end alive, try to find a 14 bolt or Dana 60. The 12 bolt will last for a bit if you're easy on the throttle and know when to stop.

I thought 12 bolts had c-clips. If so, go 14 bolt. Personally with 38's I'd go with at least 4.56's, just MHO.