[WasteOfMoney]

I'm looking for a rear posi unit or a locker for my 1994 c2500 7.4l automatic. The rear axle doesn't have an ID tag on it like I'm used to seeing, I've searched and searched online and I have no clue what i have, what to get or where to start. A friend suggested Aussie Locker but I'm not sure they make a product that fits. If you can kindly help me out it would be much appreciated!

 

[11MPG]

You have an old school GM 14 bolt. The 2 schools of thought on this are a Detroit locker or a Detroit truetrac. The locker from them is tough as nails but you have full lockup when power is engaged even on turns. The truetrac is worm gear style and almost as effective but less harsh on the tires. My 2 cents, go for a Truetrac

 

[WasteOfMoney]

I'm down for saving tires! I've found the Truetrac online and I keep seeing 9.5", 10.5" and 11.5". I had no idea there were so many options in old Chevy trucks

 

[WasteOfMoney]

So the other info I need is my ring gear ratio, axle spline count, and rung gear diameter, correct? And way to ID that without removing the cover? It's an 8lug truck if that matters.

 

[11MPG]

Count the bolts on the diff cover. If you 14 then you have the 9.5. 10.5 didn't come until 1999

 

[GREENSIERRA]

take a picture of the diff and we will help you identify it

 

[DirtyBlackHD]

Count the bolts on the diff cover. If you 14 then you have the 9.5. 10.5 didn't come until 1999

Negative ghostrider. The 14FF 10.5 has been around since the 70s/80s body style.

OP with a 454, you SHOULD have a 14FF. You'll know it by it's iconic hexagon shape. The 14sf 9.5 is oval shaped. You'll also easily note whether or not it has full floating hubs.

For the 14ff, the best value is a detroit locker. They are cheap since they are mini lockers but plenty strong and quick to setup if you aren't regearing. There are many options for this axle. The best ones are ARB air locker, yukon grizzly, etc. If you're more into street cruising, a limited slip is more for you. Detroit, auburn, yukon, etc. There are also a number of other mini lockers, but i don't care for them... like lockrite, aussie, etc.

 

[11MPG]

Negative ghostrider. The 14FF 10.5 has been around since the 70s/80s body style.

OP with a 454, you SHOULD have a 14FF. You'll know it by it's iconic hexagon shape. The 14sf 9.5 is oval shaped. You'll also easily note whether or not it has full floating hubs.

For the 14ff, the best value is a detroit locker. They are cheap since they are mini lockers but plenty strong and quick to setup if you aren't regearing. There are many options for this axle. The best ones are ARB air locker, yukon grizzly, etc. If you're more into street cruising, a limited slip is more for you. Detroit, auburn, yukon, etc. There are also a number of other mini lockers, but i don't care for them... like lockrite, aussie, etc.

Thanks for saving me. Had a brain fart and meant the AAM 11.5. :drink_nl:

 

[GREENSIERRA]

I was gonna say I know for a fact that they had a 14ff in those years, my father in laws 94 6.5 turbo diesel has a FF.
my diff is out of a 77.
I love my air locker but not everyone loves the price. I love that I can cruise around with 1 wheel peel and with a flick of a switch its completely locked

 

[TPoore]

Not meaning to threadjack but I was looking into doing something similar. The rear end in my 07 feels sloppy and was looking at doing a 3.73 and Locker or something better since its hard to get the LSD to engage half the time. 07 NNBS 5.3,4l60, 3.42gear.

 

[BENT]

I just upgraded my old g80 limited slip in my 92 1/2 ton to a detroit trutrac and i really like it. g80 grenaded and took the gears out with it
i am running 3.73 with a 6.0 swap and a nv4500 transmission.
ordered mine from jegs for around 388 $ with free shipping.