posi trac

I have a 1988 c-1500 that I am customizing. I figured out that after I bought the truck that it did not have a posi lock rear in it. I was wondering if anybody knew how to tell how many splines they have without opening it up. Or a place where I can get a posi lock rear for it. Or even better, another car that has posi that would bolt right up the the springs and driveshaft.

posi=worthless!!

I would just get a locker for it. Check out Detroit and other manufacturers

posi=worthless!!

I would just get a locker for it. Check out Detroit and other manufacturers

If he has a two wheel drive truck and wants to have traction for racing he doesn't need a locker a limited slip posi will perform just as well on dry pavement. If he is going off road or in snow and juch then he probaly wants a locker because the others a pretty much useless. Corvettes, Z-28's, Mustangs, Chevelles, Nova's, You name it they didn't come or do come with lockers. They all came with limited slip because it performs better in the daily driving and performs very well performance driving as long as you are on dry or even wet pavement. They even work in the snow if both wheels are in the snow, But thats where a locker shines. I put an Audurn limited slip in my Blazer and it worked great unless one wheel was on ice then it was worthless. It was basically worthless for me because that is the situation I was trying to avoid. That is when I startedlooking into the different style diffs.

I disagree. Limited slip is the only way if you plan on any street drivability!!I put a Eaton locker in my k5 blazer and it was suicide in the snow and HARD on drivetrain in the summer.cool for racing but thats it!!

I disagree. Limited slip is the only way if you plan on any street drivability!!I put a Eaton locker in my k5 blazer and it was suicide in the snow and HARD on drivetrain in the summer.cool for racing but thats it!!


I agree with you accept with most limited slips if you are in snow both tires have to be in the snow or the one with least resistance will spin. Limited slip is by far the most streetable and as I said it is what factory performance cars have. There are different types of lockers and some are definately harsher than others. Driving in snow on the street with a true locker can be a nightmare until you get used to it because you have to drive totally different than with an open diff to keep from spinning out. This is actually where the G-80 shines because it is a combination between an open diff and a true locker and not a limited slip. I put and Auburn limited slip and if both tires were in the snow it was fine. If pulled over with one in the snow or on ice and the other on dry pavement the wheel on ice would spin rendering the limited slip useless and making me wish I had a locker. The limited slips were designed for both wheels to have equal traction for performance and not for any off road or adverse driving conditions and that is why GM used the G-80 in trucks and not the limited slip that is in Camaros and such. Many people think that a locker means both wheels always turn the same speed, But that will only happen if you buy a spool or weld the spiders together. The lockers sold for the street will let one wheel over-run the other it is just some are harsher and noisier when they do this.

If you have any power, a limited slip or posi will not be able to hold.

He said he was customizing it, as well as wanting to add a posi unit. I figured he must be planning on adding a significant amount of tourque and/or drag racing the truck

If you have any power, a limited slip or posi will not be able to hold.

He said he was customizing it, as well as wanting to add a posi unit. I figured he must be planning on adding a significant amount of tourque and/or drag racing the truck
I have a 83 k20 custom delux w a punched 400 putting out oooo about 400 hp it came from the factory w a lim slp 14 bolt and it hasnt broke yet . I use this truck daily to pull a small bulldozer.I dont meen to sound like an know it all but this sure works for me !25 years of hard service & all that has been done to the rear end is axle bearings.

I have a 83 k20 custom delux w a punched 400 putting out oooo about 400 hp it came from the factory w a lim slp 14 bolt and it hasnt broke yet . I use this truck daily to pull a small bulldozer.I dont meen to sound like an know it all but this sure works for me !25 years of hard service & all that has been done to the rear end is axle bearings.


I agree a limited slip will hold up to extreme power. It is what came in factory muscle cars. For instance, 1967 L-88 Corvette 427 with 550 + h.p. and 550 ft.lbs. of torque or 1970 Chevelle SS 454, LS-6 454 with 450 h.p. and 500 ft.lbs of torque. I could be wrong but as far as I know a limited slip is what has been and is still used in muscle cars.

I have a 83 k20 custom delux w a punched 400 putting out oooo about 400 hp it came from the factory w a lim slp 14 bolt and it hasnt broke yet . I use this truck daily to pull a small bulldozer.I dont meen to sound like an know it all but this sure works for me !25 years of hard service & all that has been done to the rear end is axle bearings.

I never said it would break, I simply said it may not hold. Another words, both tires may start out spinning together (same speed...due to the posi), but then it might let up and allow only one tire to spin...if that makes sense :biggrin: .

I had a factory posi in one of my trucks ('74 chevy, 44"tsl's, and a bored/stroked 454) and If I tried to do a burnout, the posi was not able to hold. It never broke, it just wasn't strong like a locking unit.

I have a 1988 c-1500 that I am customizing. I figured out that after I bought the truck that it did not have a posi lock rear in it. I was wondering if anybody knew how to tell how many splines they have without opening it up. Or a place where I can get a posi lock rear for it. Or even better, another car that has posi that would bolt right up the the springs and driveshaft.
chek out the markwilliams.com this guy can hook you up .Sorry to get your thread into a discussion about stupid shit!!! :lol: