The Stovebolt Site Forums The Shop Area Engine Shop help identifying rear in '65 C20

Trying to find some highway gears for my '65 C20. I think I've got an Eaton rear. Not just the carrier but, the entire rear. It's a really big, round housing like **** 9" except it's got a 10 bolt cover. Found a pic on a 4x4 website that simply called it an Eaton. My buddy said he thinks Eaton did make complete rears in the 60's. It all looks pretty original to me, can't see mods anywhere. Anybody know what's up with this? It can't possibly be as rare as it seems after looking for info on the net.

As far as I know, Chevy used this rear end in 60-72 3/4 and 1 ton trucks, as well as NAPCO trucks, and maybe a few others. My 61 has it--check the link for pics. I can email you more if you want them. Mine has 4.56 gears, and i know 4.11 and 5.14 were also available, and possibly others???? I think I read somewhere that the one ton model was an H-072, but I don't remember what the 3/4 ton version was. Maybe somebody could back me up on this? Have you found lots of info on this axle? I haven't had much luck on the internet. Every once in a while parts will surface on ebay. Just saw a detroit locker go for $200, no gears included. Parts are kinda $$$$, but it makes 14-bolts look like nothing. Do you know what ratio yours is? If it already has 4.11's in it, I don't know that they made any in the 3's for this axle.

Yep, that's the one. GM H-072. Just did a search with that and the 3/4 and 1 tons used it. The only difference was the 3/4 had a 4.57 with an option for 5.13 while the 1 ton had the 5.13.
And no, I can't find much of anything on the net. I certainly haven't found anyone selling freeway friendly gears. Seems like a good, beefy rear (full floating I think) so I don't understand why gears are not available. Unless anyone's got suggestions, I guess I'll have to start looking for a cheap Dana 44.

yeah, that is one of the stronger rear ends put in a light truck. I think the reason parts aren't readily available is because it hasn't been in production for a while, and there weren't a bunch of them made. What tire size do you have? You might keep your eyes open for a set of 4.11 gears--that would help out quite a bit on the top end. I have 4.56 gears in mine, and with 235/85/R16 tires, I turn 2700 rpm at 50 mph (and i don't get much over that ). Going to 4.11's should drop about 500 rpm off of that. Here's a link to a pretty good chart on tire size v. gearing
ratio chart

Do you haul much with your truck? If you're just going to be doing freeway driving and not pulling anything very much, a Dana 44 would probably work. For much of a load, though, I'd go with a 14 bolt from a later model 3/4 or 1 ton chevy. They're pretty strong, and parts are abundant.

I've got 225/75/16 tires. Don't haul much, mostly drive. Gotta take freeways to get to work and here in SoCal the speed limit is 65. I do 60 and tach at 3200 or 3300. Gas is $2.25 right now so I'm hatin' life. Yeah, just looked on ebay and there were a couple 14 bolts complete. I just don't want to pay for shipping (unless I can get it for cheap) so I'll probably wait 'til there's something I can pick up here. I just hate to swap the original. I'm an original kinda guy.

Patricks makes a 3.90 ratio for the 3/4 rear. Gears and install kit run around $1000 US. Supposed to bolt right into the 67-72 carrier. According to the tech page on Jim Carter's site, the third members from 1947 to 1972 are all interchangeable.

I just called Patrick's about 15 minutes ago and was told (I think by Patrick himself) that they've only got stuff for 1/2 tons. I emailed Art Houser but have yet to hear anything.

Those 3.90 gear sets are around 400 bucks I think, add to that new bearings and you got an empty wallet. Get a 14 bolt GM rear from a 73 or newer truck,they come in various ratios, full floating, semi floating, see em around for 200-300 bucks, some with posi.Takes a little fabrication work to put one in a 60-72 truck, but nothing a grinder, tape measure and welder can't take care of.

Or just find a 4.11 unit from a '67-'72 at your friendly boneyard. I paid all of $66 for mine, and it seems to be fine. As of yet it isn't installed, but I am going to pull it apart and check everything before it goes in the truck. They aren't particularly common, but they do show up from time to time.

Now if anyone has one of those in positraction, feel free to send it my way!

do the 67-72's have the same control arms as 60-66 or is some welding involved?

Mugsy, it's the same basic design, can't say for sure it's identical.If you're talking about swapping a later 14 bolt into your truck,it should be close enough.The swap requires welding on the coil spring stuff,, control arm pivots etc from the old axle to the new one, adapting the parking brake cables, and a conversion U-joint is available for about 25 bucks I'm assuming your truck has coils in the back,some 2 whl drives and four wheels have leaves.If you can do the work yourself, it's a good swap, otherwise it gets expensive to have it done.I was looking for a 4.11 center section for a 68 C-20 I had, the few I found needed new bearings, then ya have to set up the ring and pinion again.

Tony,
I'm sure I could fabricate the stuff for a newer 14 bolt but, this is now my daily driver so the less work the better. Looking in the LMC catalog under "How To Identify Your Differential" they show a 10 bolt and 12 bolt, Dana 44 and Dana 60? I think. Doesn't show my rear of course. So, I'm thinking (hoping) that some 60-66 GM 3/4's came with these which should just be a bolt-in and $200 + misc. for freeway gears. That's where I'm leaning right now. Can I find one? That may be the tricky part.

Check the Tech tips on Jim Carter's site. I believe the 4.11 only came 67-72 for the 3/4 drop out rear. If you find one, it is an absolute straight swap. If your truck sits high like mine, you don't eve have to jack it up! Pop the axels at the hubs, unbolt the pumpkin and u-joint, repeat in reverse. The rear end housing doesn't move during the swap. If you use the 14 bolt, you end up having to do the machine work.

Hey Mugsy, Check out Randy's ring and pinion. They are pretty helpful on that rearend stuff. They probably will be able to find any gears you want.

Pal, Yeah I've checked out Randy's. They've got a 3.90. It's better than 4.57 but not much. And I'd imagine it's close to $500 like Art Houser.