rear end question

[purehess]

i have a 91 that had a 10 bolt rear with 3.73 gears on 35" tires, i broke that rear and put a gm 12 bolt on ( found it on a 75' blazer in a junk yard) i roll with a bunch of jeep guys who take tough trails, i want to have confidence in my ride, im gonna get 4.56 gears and lockers, is the 12 bolt gonna hold up or should i pony up more $$$ and go with a 14bolt,
thanks

 

[NorCal_Chris]

Some people have success with a 12 bolt and 35s, hell even bigger tires than that.

I would say that if your gonna have a locker, and air down and do some hard wheeling you would be better off with a 14b. Its just something you wont have to think about whenever you are spinning on a rock and hook up. I think the 12 bolt would be toast.

 

[72blazerguy]

I've been running a 12 bolt in a 71 blazer w/ 35's, 4.56 gears and a detroit for several years and have never broken a rear axle. It holds up to moderate abuse and has been great in Moab and around CO (I have a 14bff for it, but haven't had the time and money to make the switch). I always carry a spare rear axle on the trail. OTOH, one of my wheeling buddies blew up a rear axle fairly often until he went with the 14 bolt. So basically, it depends on your driving style.

A big drawback to the 14 bolt is the clearance issue with 35's. Same buddy mentioned above is always dragging the 14 bolt over rocks with 38's that I clear with the 12 bolt and 35's.

 

[Navy75]

i run a 10 bolt in mine and haven't had any problems yet. but i did come across a 14b sf with 6 lugs. the guy couldn't tell me what it came out of.
appeared to be locked (don't know with what) and he only wanted $100 for it.
does anybody have an idea as to what had these axles and if they are worth a darn?

 

[Big Blzn]

i run a 10 bolt in mine and haven't had any problems yet. but i did come across a 14b sf with 6 lugs. the guy couldn't tell me what it came out of.
appeared to be locked (don't know with what) and he only wanted $100 for it.
does anybody have an idea as to what had these axles and if they are worth a darn?

That 6 lug 14bolt may be worth probably twice what a standard 14BFF would cost. Much harder to find and people like the extra beef and strength while keeping their 6 lug / half ton rims. Jump on it if you can.

 

[Navy75]

cool, will do