69 c50

[Pvmt-Pndr]

Thanks for the replys guys! So as I learn more and more about these trucks I'm liking them more and more!

If it turns out to have a 366 vs a 350 to me really doesn't matter. I just found it odd that someone potentially can't tell the difference between a small block or a big block and wanted to confirm what I have been learning. I'll keep you guys posted on what it turns out to be.

[sweetk30]

valve cover = 4 bolts on small block chevy

valve cover = 7 bolts on big block chevy

exhaust manifold = 1-23-4 ports like this on small block chevy

exhaust manifold = 1-2-3-4 ports like this on big block chevy

[Pvmt-Pndr]

I can tell the difference. It just poses more questions I have for the current owner. My wife's truck has a 366 in it right now so we're quite familiar with it and who hasn't owned at least one 350

[Pvmt-Pndr]

Alright guys I'm still waiting on some pictures of the tires and the engine to verify that it is or isn't a 350. It is definatly a 4 speed.

Couple questions. With this setup the way it currently sits what should I expect for mph with it being nine stock?

Apparently there was a vacuum leak at some point in time so the rear is stuck in high. If I assume it's worse case and I can't fix it for a decent price right away how should I assume it will pull 10k pounds without having low in the rear end?

[Nobighurry]

Make sure it is vacuum 2 speed; I haven't seen vacuum switches in those years, all I've see nc are electric switched.
As for towing, I think you'll be fine, but expect slow starts.

[Pvmt-Pndr]

His wife did tell me "all that is there is 2 wires so the speedometer is correct".
I'm not knowledgeable enough to tell the difference between the two. Can you or anyone enlighten me. I'll be doing a lot of research on all of this over the next few days. I'm going to get eyes on it this weekend as long as our schedules work out.

Any ideas on top speed?

[Nobighurry]

If it is electric, there are 2 wires running to the switch on the rear end. You can ohm the wires to determine which is high and which is low. Then make sure your switch on the shifter is aligned to the right wire. Pretty simple.

I took mine out today, is a 1970 c60 with 366 and 4 speed. I topped out at 55. Possibly could have gotten more but I was happy with that.

[Pvmt-Pndr]

That sounds simple enough to figure out. If it's claimed a vacuum leak on an electric setup what could be the issue? More important what's a round about price to fix it? I know it's a loaded question.

55 might just work for me. Lots in question now. Thanks

[Nobighurry]

I've never messed with the vacuum switches. On the electric, if the wiring is good, you can probably just take it apart and clean it. I have no details on how to do it, but I've been told it is easy.

[Pvmt-Pndr]

Any idea what rpm you were turning while you were doing 55?

Since I have a red flag or two so far I'm starting to reconsider. If the tires are bald I'm not even going to bother is what I'm telling myself right now

[Nobighurry]

A little over 3k rpm. Tires aren't cheap. 20" are hard to find. Changing over to 22.5 is best, but still not cheap. A little easier if it has Dayton wheels.

[Pvmt-Pndr]

I believe they are dayton rims since they're 10 lug but I'm not completely sure either. A set of tires would be more then what I may be spending on the truck.

3k at 55. I don't mind cruising at 3500 or so at all so 60 might just be within reach.

Once I get the few pictures I'm still waiting for (it's cold and dark here so I don't expect pictures until tomorrow). I'll do some more searching around and learning about the rear end. From there I'll decide if I still want to take the trip to check it out. I'm starting to think it'll be a money pit. I'm ok with money pits as long as it does everything I want from the get go. From there I can upgrade over time. If it doesnt make sense it doesn't make sense. Thanks for all your input guys.

[C10 - C90 Bill]

The 2-Speed Rear should be Electric as a few have mentioned. Always check the simple things first. Could be just a broken wire somewhere.

I haven't fooled with tires for years, but years ago buying used school bus tires used to be a good option. They take them off pretty early. If the sizes are right.

[Airdirect]

Two speed rears are usually either electric or vacuum. The old Chevrolet rears were shifted by a vacuum cylinder. The vacuum cylinder was controlled by a mechanical cable to a vacuum valve. The cable was like a choke cable attached to the shifter which you would pull up or push down. In addition they had a small link between the vacuum valve and a two speed box on the speedometer cable. This allowed the speedometer to be adjusted for hi and low rear gearing. Some had a vacuum valve mounted under the dash that you would shift left to right for low to hi.

Most of the vintage you are talking about were vacuum. The vacuum was generated by the intake of the engine. Easy to trace and fix, usually a broken vacuum hose. Worse case would be the cylinder diaphragm is busted. Either way it should be easy to fix.

Later years they switched to electric. My 1979 is electric. It has a dc electric motor that moves the rear between high and low just like the vacuum cylinder above. The motor is controlled by two wires, red and black. The two speed selector switch receives power via a green wire. It applies power to the black wire for low speed, and the red wire for hi speed. The black wire also feeds power to an electric speedometer adapter unit, in line with the speedometer cable, to adjust the speedometer gearing when in low. The motor and speedometer adapter both must be grounded. Do not apply power to both the black and red wires at the same time or you will let the smoke out of the motor and it will cease to operate.

On the electric unit, the first place to start would be the fuse panel, looking for a blown fuse.

Here is a link to my two speed rear end. I upgraded the gear ratio by changing the ring and pinion.

http://67-72chevytrucks.com/vboard/s...d.php?t=729084

[Nobighurry]

Originally Posted by Airdirect

Most of the vintage you are talking about were vacuum.
]

GM was doing electric as early as 1970

[C10 - C90 Bill]

All our and my own GM and IH trucks were Electric. The '62, '64, and '67 as well as all the trucks I rode in, rented and looked at for sale. I cannot even remember a Vacuum on an early 60's and newer.

[Pvmt-Pndr]

While I'm still waiting on pictures of the tires and engine I've been looking up transmissions.

I found these two that are the only 2 OD options 5 speed transmissions from the era the Spicer 3153 5-Speed and a Clark 264VO 5-Speed both geared very similar. Both are basically .80:1 final drive. Any thoughts on how hard these are to find or to swap? I'm worried that 55 mph with the 4 speed I would get ran over. Highway speeds where I live and travel is 70-75 mph.

[Airdirect]

My maintenance manual for 1979 still shows both electric and vacuum available. I know the vacuum was used into the late 70's on school bus applications.

[Nobighurry]

Originally Posted by Pvmt-Pndr

I'm worried that 55 mph with the 4 speed I would get ran over. Highway speeds where I live and travel is 70-75 mph.

While I don't really do much interstate driving, I certainly never worry about getting run over - there aren't many vehicles on the road today that want to tangle with 50 years of real steel. Slow or otherwise

[Pvmt-Pndr]

I'm not too worried about the rear end now as long as it pulls my 10k pounds without too much of a struggle without having the low in the rear end. I'm pretty confident that I will be able to figure that out.

My main concern now is the top speed and finding a usable 5 speed with over drive that will stay together. Since its a fixed rear end currently may be even an automatic.

[Pvmt-Pndr]

Originally Posted by Nobighurry

While I don't really do much interstate driving, I certainly never worry about getting run over - there aren't many vehicles on the road today that want to tangle with 50 years of real steel. Slow or otherwise

Semi trucks can do 75 when I'm headed north about 2 hours from me. That's a battle I know I wouldn't win

Most of my driving will be on the expressway too

[C10 - C90 Bill]

Originally Posted by Airdirect

My maintenance manual for 1979 still shows both electric and vacuum available.

That's interesting. Wonder if that was one of those "regional" things like the wheels were.

Originally Posted by Airdirect

I know the vacuum was used into the late 70's on school bus applications.

Wow, I remember where school bus drivers had a hard enough time with a Manual Trans. I can't imagine throwing in a 2-Speed as well.

But that is also another first. Never ever saw a school bus with a 2-Speed Rear.

[Pvmt-Pndr]

I've made a plan to look at it this Saturday. The engine is currently out of it. I have 3 different options on buying it.
1) buy it without the 350 - $1800.
2) buy it with the engine, not installed - $2200.
3) engine installed ready to go - $2500

Knowing that it has some issues and things that have to be done right away to be usable... and I do the work on all of it myself. Keep in mind I did have back surgery in December and the Dr said not to do anything stupid for a year...
1) brakes booster/master cylinder $100-500ish
2) possible unknown other issues with the brakes $100-600.
3) 2 speed rear end isn't usable and to make fixable, no switch on the shifter and is missing (guessing) $100-400.
4) a 24k pound gooseneck needs installed $500 ish
5) some sort of OD transmission installed so it will do 65+ mph, trans + whatever I need to fabricate to make it work (guessing again) $1000-2000.
6) trailer brake switch $100-300

If I go with option #3 for buying it so I can drive it onto a trailer and move it around the yard when I need to and go with the high side of my guesstimate on price to make it usable for me I would be $4300 to make it work plus $2500 for the truck which adds up to $6800.
On the low side it would be $1900 + the price of the truck 2500 would put me at $4400 for a tow pig that would do everything I want it to do.

Another thought worth mentioning. The current owner said that high in the rear end is a 6:50 gear which tells me it's a GM axle with a low gear of 8:85 which in searching and doing my home work I've come to find out that you can no longer get parts for that axle if something did go wrong. Going hand in hand with what a few people have said and what I have found on the internet, doing 55 mph the 350 would be turning 3000-3200 rpm. How fast can these 350s turn comfortably and for how long? I would also like to hear opinions on gear swaps or possible rear end swaps that would suite me pulling up to 20k pounds and be able to do 65 comfortably.

In the pictures of the motor that they sent me it looks to me and most of this is judging off of the valve covers that the 350 is not original to this truck. The valve covers look like they've never been off and it says 350 GM Goodwrench which I assume the original valve covers from 69 would not say that. It looks as if it's a crate motor if I had to guess.

Since I've throw all the numbers out there I'm not convinced this is the truck for me. Any thoughts good or bad I want to hear them. $5k was the cap that I originally had in my mind for a truck that would do what I want. That's weather I pay 5k for a truck ready to go or in this case buy for 2500 and is be willing to put another 2500 into it. From there I would upgrade down the road and make it my dream truck as time goes on.

[Nobighurry]

I paid $2300 for a running and drivable ex-firetruck with 30k miles. Being an old firetruck, it was taken care of. That said, I have exceeded your price cap with my repairs, updates, etc. Some parts are hard to find and can be pricey if you do locate them. Do most of my work myself.

A lot of the sheetmetal is no longer made, so you'll need to source donors.
Not trying to talk you out of it, I think these trucks are great, but these certainly aren't cheap hobbies.

[Pvmt-Pndr]

CURVE BALL FELLAS!!!!!

As we know I had my heart set on this C50 we've been talking about. Just my luck i looked around today there is a 69 C60 with a 427 and a 5 speed with a 2 speed rear end posted for $2k 2 and a half hours away! I'm going to look at it tomorrow! It's much cleaner then the C50