I have some questions, since this is my first C20.
1. I am missing the front yoke for the driveshaft (I think that is what it is called). Anyone know where I can find one? I have the driveshaft, but only a yoke on one end.
2. I have heard some people get rid of the 16.5 wheels and install C10 disc conversions in the front and change the rear end to the C10. Is this a good idea? Is it difficult finding tires for the 16.5 wheels?
3. Is a 5-speed trans possible, will it bolt right up?
4. Does anyone have a diagram that shows the coil-distributor wiring?
I have some questions, since this is my first C20.
1. I am missing the front yoke for the driveshaft (I think that is what it is called). Anyone know where I can find one? I have the driveshaft, but only a yoke on one end. 2. I have heard some people get rid of the 16.5 wheels and install C10 disc conversions in the front and change the rear end to the C10. Is this a good idea? Is it difficult finding tires for the 16.5 wheels? 3. Is a 5-speed trans possible, will it bolt right up? 4. Does anyone have a diagram that shows the coil-distributor wiring? Thanks!
Looks like I do have the driveline parts I need, except for the ujoint.
Please post the year, engine size and transmission type when asking questions. Thank you.
Martin '62 Chevy C-10 Stepside Shortbed (Restomod in progress) '47 Chevy 3100 5 Window (long term project) ‘65 Chevy Biscayne (Emily) ‘39 Dodge Business Coupe (Clarence) “I fought the law and the law won" now I are a retired one! Support those brave men/women who stand the "Thin Blue Line"! Hug a cop! USAF 1965-1969 Weather Observation Tech (I got paid to look at the clouds)
Before you get to technical, it would be good to include what year.
In general, for the coil, you will have two wires to the coil. One is a resistance wire, the other is from the "R" terminal on the starter solenoid. The resistance wire goes to the fuse panel. If you no longer have the special resistance wire you can use a ballast resistor. Advise.
Check your local tire shops for availability of 16.5. It may be a local or regional availability.
Get it running and driving before you go changing to all kind of half ton stuff. Bigger brakes, suspension and load capability are all good things. I dig it for what it is....a truck.
Get it running and driving before you go changing to all kind of half ton stuff. Bigger brakes, suspension and load capability are all good things. I dig it for what it is....a truck.
Yes - of course. Just trying to get the thing rolling right now. But I need to get some questions answered so I can think about which direction to eventually go.
Is there a place online that shows exploded views, like a microfiche?
The '63-66 C-20 is basically the same truck.. The 292 6cyln is an excellent engine, in good condition it will run off and hi,de from the 283 V8. The 4spd trans is a brute, almost indistructible. The rear ends are also very stout, generally the ratio is 4.56 which makes the truck all done at 60+. If you want a good reliable work horse just repair the mechanical components as needed. If you want the truck to drive better at highway speeds pick up a donor truck, '72 or later C20. swap out the complete front end, it is a bolt in application. That will give you PS, Power disk brakes. The '72 and later 4spd's are nice transmissions, a little more user friendly, a 400th trans or a 700R4 AOD would be an up grade. General speaking the rear axle in a '72 later C20 will be a 4.10/3.73, much better highway gearing. I don't care for stick transmissions, however, if you are going to do a lot of towing the sticks hold up better. If you want to make the truck into a 1/2 ton then use a C10 truck as a donor. My brother has a '64 C10 that started life as a C20, it had been rolled prior to him buying the truck. We stripped the truck down, changed the cab to a big window, used '81 C10 running gear, a 200R4 OD trans and a 350 trans. It is a very nice stock looking truck that has won several awards at car shows. My own '64 started it life as a C20 special built extended cab. I put the body on a '97 C10 extended cab chassis, 5.7 V8, 4L60 trans, 342 rear end with a 6ft fleet-side bed in lieu of the step side. pretty neat truck. The moral to this story is, don't get in a big hurry to tear the thing apart until you are sure what direction you want to go. Wm.
The '63-66 C-20 is basically the same truck.. The 292 6cyln is an excellent engine, in good condition it will run off and hi,de from the 283 V8. The 4spd trans is a brute, almost indistructible. The rear ends are also very stout, generally the ratio is 4.56 which makes the truck all done at 60+. If you want a good reliable work horse just repair the mechanical components as needed. If you want the truck to drive better at highway speeds pick up a donor truck, '72 or later C20. swap out the complete front end, it is a bolt in application. That will give you PS, Power disk brakes. The '72 and later 4spd's are nice transmissions, a little more user friendly, a 400th trans or a 700R4 AOD would be an up grade. General speaking the rear axle in a '72 later C20 will be a 4.10/3.73, much better highway gearing. I don't care for stick transmissions, however, if you are going to do a lot of towing the sticks hold up better. If you want to make the truck into a 1/2 ton then use a C10 truck as a donor. My brother has a '64 C10 that started life as a C20, it had been rolled prior to him buying the truck. We stripped the truck down, changed the cab to a big window, used '81 C10 running gear, a 200R4 OD trans and a 350 trans. It is a very nice stock looking truck that has won several awards at car shows. My own '64 started it life as a C20 special built extended cab. I put the body on a '97 C10 extended cab chassis, 5.7 V8, 4L60 trans, 342 rear end with a 6ft fleet-side bed in lieu of the step side. pretty neat truck. The moral to this story is, don't get in a big hurry to tear the thing apart until you are sure what direction you want to go. Wm.
To reply to your question about the 16.5 tires/wheels. The 16.5 tires have been pretty well out of stock for almost ten years. There are some off road 16.5's available, however, you would not want to use them for general driving. The later model 8 lug 16" will fit right on your truck, use a 235/75R16 tire, or larger to overcome the low rear axle ratio. If you like to spend money and make the truck user unfriendly, forget about switching the trans to a 5spd. The TH400 was an option in the '66 and later trucks, however, the engine was generally a 327 V8. The '65 C20 Camper Special I bought new came with a 283 V8 and a 2 spd Powerglide.. A terrible power combination. I changed the trans to a TH400 in '67. Big improvement. In '68 the 283 was dead with 49k on it, I re-powered the truck with a '68 350 hp 396 out of a wrecked Caprise, 2,300 miles on it. I drove the truck for 18 years with no issues, the man I sold the truck to still owns it. I have tried many times to buy it back, he won't sell it, it is his every day truck. The coil wire you have referred to is a very small green wire, which is a special resistance wire that allows 12v to the coil for starting, then as it warms up it chokes the voltage down to somewhere around 6v. This resistance wire acts in lieu of a ballast resister. Wm.
Last edited by Wm L; 04/22/20203:11 PM. Reason: spelling
An added thought on your truck.. Reviewing the pic you attached I noted that your truck appears to have a floor mounted emergency brake that is attached to the back of the transmission, the drive-line then attaches to the back of brake hub in lieu of having a slip yoke. If my assumption is correct you have a problem with changes to your trans because in doing so you will eliminate the hand brake. If you go forward with a trans change, you will have to find a hand brake assembly out of a '64-66 C-10,20. Wm.
To reply to your question about the 16.5 tires/wheels. The 16.5 tires have been pretty well out of stock for almost ten years. There are some off road 16.5's available, however, you would not want to use them for general driving. The later model 8 lug 16" will fit right on your truck, use a 235/75R16 tire, or larger to overcome the low rear axle ratio. If you like to spend money and make the truck user unfriendly, forget about switching the trans to a 5spd. The TH400 was an option in the '66 and later trucks, however, the engine was generally a 327 V8. The '65 C20 Camper Special I bought new came with a 283 V8 and a 2 spd Powerglide.. A terrible power combination. I changed the trans to a TH400 in '67. Big improvement. In '68 the 283 was dead with 49k on it, I re-powered the truck with a '68 350 hp 396 out of a wrecked Caprise, 2,300 miles on it. I drove the truck for 18 years with no issues, the man I sold the truck to still owns it. I have tried many times to buy it back, he won't sell it, it is his every day truck. The coil wire you have referred to is a very small green wire, which is a special resistance wire that allows 12v to the coil for starting, then as it warms up it chokes the voltage down to somewhere around 6v. This resistance wire acts in lieu of a ballast resister. Wm.
Is the resistance wire available, or is it just easier to use a ballast resistor? Does anyone have a wiring diagram they can supply?
I have factory manuals that show the routing of the primary wire to the coil, the wire in question is very small and a medium green color. As I recall the secondary wire, coil to distributor is black. I'll check my trucks, '64-66, and look in the manuals. The green primary wire would be within the loom coming through the firewall from the ignition switch. I had a lot of starting trouble with my original '65 in the mid 70's. Heat build up in the main loom restricted the current flow within the wires. High engine compartment heat was the culprit. This was a very common problem in '65 to late '70 C10,20 trks. I would think that the special resistance wire would be available from one of the aftermarket vendors. I don't think it would work to well to try and splice a new piece of wire to the old wire. Unwrap the loom to find out just were the original wire stops. I am not to sure just how well the wiring in of a ballast resistor would be, taking in consideration the Start/Run feature built into ignition switches that utilize resistors. Wm.
Also, unless you are a metal expert in rust repair, when doing a future restoration, stick with either all aftermarket metal or fix all the original metal, don't mix and match, it will be a nightmare. Key Parts has good aftermarket thickness guage metal for these trucks.
Just an FYI, the hood in the bed of that truck in the picture is a 60 or 61, only the chevy 62-66 had the same hood.
[quote=BC59][quote=RustYardDog] Just an FYI, the hood in the bed of that truck in the picture is a 60 or 61, only the chevy 62-66 had the same hood. ]
Very good call BC59, when I reviewed the pix again I noted the floor parking brake, which I should have noted when I looked at the trans pix and noted the parking brake drum on the back of the trans. I wonder ? Is the front end suspension torsion bar or independent A arms. The 60, 61 & 62 had torsion bars in lieu of springs. The '62, 63 share the same dash, where-as the '64-66 have a completely different dash. The '63 front end is A arms/springs. Wm.
The easiest 5 speed swap will be an np540 from a bigger truck. If you find a GM version, it's a bolt in, and it will come with a parking brake on the rear just like your current transmission. Some versions of the np540 had an overdrive, but they are rare.
Liquidated my projects Now looking for a decent '47-'55.1 3100, 3600, or 3800
The easiest 5 speed swap will be an np540 from a bigger truck. If you find a GM version, it's a bolt in, and it will come with a parking brake on the rear just like your current transmission. Some versions of the np540 had an overdrive, but they are rare.
Will the NP540 make a difference in gearing, cruise speed? I will still need to swap the rear end, correct?
Woops, made a mistake on the primary coil wire routing. I had misplaced the GM manual showing the wiring diagrams, I just found the manual. Seems that my memory was a little off. Reviewing the diagram I noted that the primary resistance wire to the coil runs from the R terminal on the starter solenoid, then to the + terminal on the coil. The solenoid gets its power from the battery to the B terminal on the solenoid. There is a wire coming from the key switch to the R terminal on the solenoid, this wire energizes the solenoid. If you want to PM me your phone number I'll send you a copy of the wiring diagram for your truck. The addition of the NP540 5 spd will do nothing to improve the highway speeds for you. The transmission you have with a later model 4.10 or preferably a 3.73 and 235/75R16 tires would do wonders for you truck without braking the bank. If you could find a 5 spd OD trans, they are New Process of Clark.. I had a 72 6500 GMC for many years that had a Clark 5 spd OD trans. During my travels I have found that the 5 spd OD trans that would fit your truck were more common in school buses, especially in rural area where the bus traveled great distances. The truck you have is on the cusp of being a HD work truck in lieu of being a highway cruiser intended for the RV trade.
