I have a 1979 Chevy 1/2 ton (Silverado) 2WD truck, that has a 12 bolt rearend. I was "told" from the guy I bought it off of, that it had 3:08 gears in it. From reading several other posts on this site, I've seen that this was a common ratio. I'm wanting to change the ring and pinion over to 3:73 gears. Do I need to change the carrier as well? I haven't verified that it has 3:08's in it first hand, but can tell they're higher gears. If it helps, the truck is a "Heavy Half" 1/2 ton, originally had the 454 V8 (305 now), TH400 transmission, heavier suspension, etc... I've found a few "new" ring and pinion sets on Ebay for a reasonable price, just wondering if I need to start looking for a good used carrier to match up with the 3:73 gears or not. Thanks for any advice you guys might be able to give.

The truck 12 bolt uses two different carriers

The 3 series is for 3.40 and numerically lower gears.
the 4 series is for 3.73 and numerically higher gears.

But, if you are purchasing new gears, 3.73's are available to fit the 3 series carrier!

Hey, local boy huh

why not upgrade to a posi at the same time?

Well if I can find a used posi carrier cheap enough, I might go that route. One thing I found out today, (from one of the guys at Hardy truck parts) is that I evidently can use a spacer if I decide to keep the original carrier. What are your thoughts on going that route? I'll have to check with a buddy of mine who has a salvage yard, to see what he has in the way of of posi carrier.

OddRodder, I don't remember seeing your rig around town before, but it may be because I just wasn't looking! LOL I'll try to get some pictures of the truck online soon.

Spacers are generally considered less that optimal, this does not mean it won't work fine for you cause it probably one just not an idea situation, I don't speak from personal experience though I've never used one.

I've had it at Steak and Shake a couple of times last summer! It's still a work in progress! I actually live out of town -- west on 266 (Chestnut Exp.)

Gametech, you going out to autofest at the fairgrounds Sat.??



Gibberish!! I have used ring gear spacers on cars with 400+ h.p., as long as you use longer bolts and torque them properly, you won't have any problems!

Several years ago I used to own a 1963 Chevy Impala Station Wagon (tan in color) that I used to take to Steak & Shake. Changing the pumpkin out on it was easy. I remember picking up one from R&R in Aurora that had a 3:67 in it, ran great!



I have to work, but if I can get away long enough during my lunch break, I'll stop by. It's gonna be a cold one though!

There are some pictures of the truck online now in my gallery. I'll keep watch on some of the ring and pinion sets on Ebay, and try to get ahold of my friend who owns the salvage yard about the posi carrier

Well I wasn't suggesting that it won't work but in an idea world it would be better to not use one

Sorry Robin, I just meant that your post was hard to understand.

Well... it's worse than I thought. I jacked up the rearend, and not only found I have an open carrier, but found out I have a 2:73 ratio. (No wonder it does so good on the highway...LOL) Looks like I need a different carrier, instead of just a ring gear spacer. With the higher ratio, would that be a series 2?