1966 Rear End Question

[gaelicdog]

I have become the guy I used to hate! Someone with a cherry "barn find". I think I just scored a 1966 Chevrolet C-10 "BARN FIND". I have known the truck for 25 years, always parked in a local barn but the owner would never part with her. Finally a few years ago she was retired, but still not for sale. Well, the owner called me a few days ago and I think we may have a deal!!

This will move to the front of my project list to become a bullet proof daily driver.

It will be a few days before I can get back under her and I am curious. What was the factory rear end in a 1966 C-10? 10 or 12 bolt? If I determine her rear end to be weak () what is the readily available, the right length and strong enough for a healthy 283 4spd?


Thanks for the input!

Jerry

[LILRED66]

gaelicdog:

Welcome to the forums from Kansas City, KS.

The factory rearend was a 3.73:1 ratio, 12 bolt (at least on the cover) and it is plenty strong to run behind a 283/4-speed combination, especially if your engine/tranny is factory stock. A 3.08:1 or 4.11:1 was also available in the '66 Chevy C10 (1/2 ton) trucks.

Don't forget to post some pictures when you get her home...nice find, by-the-way.

[gaelicdog]

Thanks for the welcome.

The 283 I have is a 60 over, steel crank, double hump heads, Edelbrock intake, holley 600cfm and a pretty narley hydraulic cam with a muncie 4 speed. Should be enough to move her down the road. I want to do 4 wheel disc brakes and the remainder make it as simple as possible. Let's face it, off the track racing is no longer worth it so all I want is a bullet proof, coast to coast cruiser that I can drive daily. Is that so much to ask?

[Rogue]

I have a 327, and running that thru a WC T5 and 3.73 posi.
I have seen them hold much more than that.
Also going for the Billetproof daily driver.
If I want to go, I want to check the oil and roll out.

Congratulations on the acquisition.

[gaelicdog]

The goal, at least for now is: Simple, bullet proof and repairable on the roadside if need be.

Healthy engine, not too much and not too complicated.
4 speed
4 wheel disc brakes
Simple electronic ignition. Have even thought about old style points distributor and carry extra points
1 wire alternator
serpentine belt pulling flex fan and alternator
large aluminum radiator
Shorty headers for ample clearance
I am even rethinking the hydraulic cam. Soilds are easy to adjust and pretty much fool proof

[gaelicdog]

The rear end turned out to be a 12 Bolt and the best I can tell is it is around a 4.11, not a posi unit though.

I've had the truck for about a year now and still gather parts for the V-8 conversion and updating. So far all I have done is flushed the tank, added an in-line fuel filter, rebuilt the head and carb, replaced a few odd and end parts and replace the dry rotted tires.

Everything on the old truck works even the original radio. I drive her most weekends and get more satisfaction from it than I do my new truck.

Sadly, I have been slow to post any pictures of the "barn find" but here she is.



Lot's of patina with almost no rust!


And the 74,000 miles showing is all original with documentation.


How she looks today, although not a good pic,

[bama63]

nice find! personally i would stick with the mid 70s hei, simple and dependable 1 wire hookup and the hydraulic cams now are available from stock to hi rpm and adjust once and forget about it. it pretty much falls into personal preference and what you want from your engine and how often you like to open the hood and again NICE FIND!

['65Burb]

Another labor and cost savings I would recommend is forget the discs for the rear. They are not worth it given that your front brakes do 75% of the stopping. Also, the hassle of working on putting a new emergency brake set up is also not worth any gain. I put discs on the rear of a '36 Ford I built up and now realize it was not worth it.

[nomrlz]

very nice. my sons 66 came with a freshly rebuilt 283 and double humps. it runs purdy good.

[gaelicdog]

Originally Posted by '65Burb

Another labor and cost savings I would recommend is forget the discs for the rear. They are not worth it given that your front brakes do 75% of the stopping. Also, the hassle of working on putting a new emergency brake set up is also not worth any gain. I put discs on the rear of a '36 Ford I built up and now realize it was not worth it.

Agreed, lot's of thoughts have changed since the original "find" and original post.

I was going to put the gas tank under the rear of the bed then realized for my needs it was not worth it. I am just going to replace the rusty one with a new one behind the seat and utilize all new fittings and hoses. Good enough.

Same thing happened with the rear brakes. While it looks good on a show truck or in racey application and on TV it is just not going to be worth it to me.

[Rich 5150 69]

I`m in preference with a 350 and HEI, auto, air, torque values are good for the weight, life is good this way, no shifting, no sweaty days and no trouble, MPG is good too.

[jocko]

nice find!! that looks like it's in great shape. I've strangley got the glovebox ID that says the original owner opted for the 3.08's that Tony mentions. But the rear end in mine turned out to actually be the stock 3.73's. So, someone must've changed em to the 3.73's at some point in time. Anyhoooo, I'd say I would have preferred 3.73's until I started driving this thing every day - which is why I am chiming in - you mentioend you had 4.11's and are want a 4-speed. If I'm not mistaken (and I am often) I think the stock 3-speeds and most 4-speeds share a final drive ratio of 1:1 (i.e. 3rd in a 3, 4th in a 4-speed). I can tell you that in 3rd gear with 3.73's - i'm winding about 3000 rpm to cruise the highway at 70. Unless you're planning a tremec or one of those rebuilt muncies with the overdrive 4th - AND you want to use it as a daily driver.... might want to consider lower (numerical) rear like a 3.55 or 3.23. All depends on trans choice of course - me personally, I'm leaning toward a tremec, but that's a ways (and a lot of $) further down the road. Considered the o/d muncie, but it had the 2.20 1st and only something like 11% o/d, so not exactly a gas saver like a TKO, etc.

As for the ignition - I agree with others on the thread, points are just a pain in the butt. I've got the old dwell meter and stuff and am remotely handy at setting the points, etc - but I'm not too proud to say I wish I didn't HAVE to do it so often. Bottom line is that the points are less than perfect after the first time you turn the key on a new set, they then start to degd. However, I'm not a big HEI fan for old motors - they work great, but the engine just loses that ol skool look immediately with an HEI. I'm still running points, but plan to switch to a Pertronix II pretty soon. Stock distrib, no mo points.

That's my 2 cents, and that and a dollar won't get you a cup of jack.

Have fun - that's a great looking truck, congrats!
jocko

[markeb01]

I can see why you had your eye on it for 25 years, that's a nice looking truck. I've always been a fan of solid lifters, love the sound especially with headers. But I no longer have the enthusiasm for that kind of routine engine maintenance.

I'm with the others on ignition - HEI is simple and dependable. I've been running one since the 80's. I'd prefer an old points distributor with a Pertronix kit, but have no justification for changing just for cosmetics.

[blackedoutharley]

As mentioned in many other threads you can also effectively change gear ratio by increasing the O.D. of the rear tires.

This can serve several purposes; one it may give you the look you want and fill up the fenderwells. It will also help ride quality somewhat as a larger sidewall will flex more thereby providing a "cushion".

I also can't recommend 3.42 gears for our trucks enough. Great balance of performance while making freeway flying much more enjoyable.

[jocko]

Originally Posted by jocko

nice find!! that looks like it's in great shape. I've strangley got the glovebox ID that says the original owner opted for the 3.08's that Tony mentions. But the rear end in mine turned out to actually be the stock 3.73's. So, someone must've changed em to the 3.73's at some point in time. Anyhoooo, I'd say I would have preferred 3.73's until I started driving this thing every day - which is why I am chiming in - you mentioend you had 4.11's and are want a 4-speed. If I'm not mistaken (and I am often) I think the stock 3-speeds and most 4-speeds share a final drive ratio of 1:1 (i.e. 3rd in a 3, 4th in a 4-speed). I can tell you that in 3rd gear with 3.73's - i'm winding about 3000 rpm to cruise the highway at 70. Unless you're planning a tremec or one of those rebuilt muncies with the overdrive 4th - AND you want to use it as a daily driver.... might want to consider lower (numerical) rear like a 3.55 or 3.23. All depends on trans choice of course - me personally, I'm leaning toward a tremec, but that's a ways (and a lot of $) further down the road. Considered the o/d muncie, but it had the 2.20 1st and only something like 11% o/d, so not exactly a gas saver like a TKO, etc.

As for the ignition - I agree with others on the thread, points are just a pain in the butt. I've got the old dwell meter and stuff and am remotely handy at setting the points, etc - but I'm not too proud to say I wish I didn't HAVE to do it so often. Bottom line is that the points are less than perfect after the first time you turn the key on a new set, they then start to degd. However, I'm not a big HEI fan for old motors - they work great, but the engine just loses that ol skool look immediately with an HEI. I'm still running points, but plan to switch to a Pertronix II pretty soon. Stock distrib, no mo points.

That's my 2 cents, and that and a dollar won't get you a cup of jack.

Have fun - that's a great looking truck, congrats!
jocko

Blackedoutharley makes a great point below... forgot to mention that my tires are 29 inches tall....

[gaelicdog]

I will go with the taller gearing, the 4.11 has to GO. The 6 cylinder will run a whopping 55mph and I can only imagine what the mileage would be with the new motor.

It's funny how when you get back to actually working on the truck and laying the ground work for all the changes how the plan morphs.

Yesterday I was given a 1981 donor truck. The truck has a GM crate 350 in it although it needs to be gone through. Has about 30K on the clock but started pumping some oil once he switched to synth???? So now it looks like we'll go with the 350 and Muncy 4 speed.

Oh how I would love to get my hands on a 6 speed!!!!!