can the 4.10 gearing in a 14bolt and d60 front hold up to 38in tires? I want to keep it decent gearing so it can still be driven on the highway.

What motor? How heavy is the rig? I'd probably want to shoot for the 5.13 range... Although I'm probably not a good source of info as I am going to be running 5.38s with 37"s :laughing:

The key element of your question is will 4.10 gears "hold up to" 38 inch tires. That can be answered several ways. One is the higher the gear ratio 3.54-4.10 gears are stronger then lower gears 4.27-? Whether or not it holds up depends on how you use it. That is the answer to your question. Now I used to have 4.10 gears on my rig with 38's and it was fine on the road. If you have low transfercase gears, or doubler, you will be fine off road too. It depends on what you have.

Transmission? I would say 4.56 minimum. What do I know, I'm running 4.56's w/ 35's, but I have OD.

John

i have no idea as to the weight, but i'll be running a amc360 or built 350 with a sm465 mated to a d300 with tera low. seeing that this is a new england rig it will pretty much see everything from highway to mudding to rocks. i'm pretty sure i want to go lower for the crawl alone, but if i dont have to i'd rather hold off for a bit to get some more cash so i just want to know if i'll be screwed if i run the 4.10 for a bit

Depends on you trans and t-case gearing. If it is kind of a stock, lifted, no extreme trans or t-case work for regear, and you are not a power house bb or diesel, Then use this for a general idea.

http://www.ring-pinion.com/content/calculators/RPM.asp

I run 33", 4.10 gear, with stock auto OD and small block V8, good on hwy and no compaints offroad.

I have a 454, 400 auto, 40" boggers and running 3.73s. The VSS isn't hooked up, so the motor isn't running 100%, and I don't really have a problem driving around. The tires aren't balanced, and start to shake around 60, so don't go much faster than that. Mostly mud around here, and some trials, but don't have a problem offroad. Now that I swapped fronts/t-cases, will be going to 4.56s.

You'll probably be fine Unless you hop the shit out of it. Ratio wise, I have an F250 with a 14 bolt, 4.10s and 38.5x11s behind a 2bbl 351 and a 435. I can still take off in second without trouble. I dont know how it goes on the highway, but I have had it to 45 or so by my still uncalibrated speedo- and that is as fast as I think I wanna take it.

buddy of mine got a jeep, built 350 (dunno what trans but i think its an auto) with a 14b d60 combo. 4:10's and 38's he has yet to have problems, i didnt get any big tires on my 14b yet but i dont think there will be any problems

I have a 77 k10 converted to k30 d60/14bff stock 350sb sm465/205 and ran 39.5 boggers for two years with 4.10 gears. It did just fine. When I got the money to buy gears, a detroit for the rear and setup tools I went to 4.88
It increased mileage greatly about 25-50% because the motor doesn't work as hard. For highway the 4.88 are good but off road 5.13 wood be better. I chose 4.88s because I plan on a big block and a dual range of some sort. My truck weighs 6k plus. 4.10 gears will work fine for now. I hope this helps a little.

No need in regearing the axles if you already have 4 to 1 in the xfer. 38's and 4.10 will be plenty strong and the low 1st in tranny will have decent crawl ratio for offroad. save your money for something else.