Twilight Fenrir

Questions about a '67 Chevrolet C(K)10

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Hello there,

I am considering picking up a 1967 Chevrolet, I'm assuming it's a 2wd C10,but I won't know if it's a C or a K until I go look at it...

I do know it has an I6,with a 3 on the tree manual transmission, and runs well. I have a few questions before I go look, and I might have a few afterwards...

How can I tell the difference between the 250 and 292 I6 engines? Are there visible differences in the engine, or do I have to pull #s?

I understand these trucks have awful aerodynamics, and thus I can only expect about 12mpg out of this truck. Does anyone know what gear ratio would be best to have in the back end for better fuel economy with this engine/tranny?

I have a professionally rebuilt Quadrajet sitting on the 305 in my El Camino with a blown engine, will this bolt onto the I6,or would I need to replace the intake manifold? Would doing so yield any significant difference in economy/performance?

I'm considering picking this up to be a daily driver until the body finishes falling apart, then sticking the drive train into my El Camino :P

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Edited by Twilight Fenrir (see edit history)

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First, there is no such thing as a 283 I6.  There was a 292 I6 in addition to the 250.  The 292 has a taller deck for the longer stroke, but I doubt you could see the difference unless the two were side-by-side.  Get the numbers off the block.

 

The stock carb is a 1bbl.  The Qjet not only won't bolt up, it won't be configured for that engine.  There are aftermarket intakes available for the Chevy six, but the 4bbl versions are set up for a square bore carb, not a spreadbore Qjet.

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First, there is no such thing as a 283 I6. There was a 292 I6 in addition to the 250. The 292 has a taller deck for the longer stroke, but I doubt you could see the difference unless the two were side-by-side. Get the numbers off the block.

The stock carb is a 1bbl. The Qjet not only won't bolt up, it won't be configured for that engine. There are aftermarket intakes available for the Chevy six, but the 4bbl versions are set up for a square bore carb, not a spreadbore Qjet.

Woops, I edited my original post, thanks n.n Kay, I'll pull numbers when I look. Where would they be on the block?

That's kind of what I thought on the intake... There are adapter plates between square and spread, aren't there? Or is it only the other way around? I haven't looked into this kind of thing in a while ^^; It will have to stay a single barrel then, at least until I potential transplant it into my '82 Camino. So, there's nothing I can do for its economy at the moment.

Edited by Twilight Fenrir (see edit history)

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The obvious difference on the  292 is at the thermostat housing. It looks taller.

I cant really see very well in your pic but I think yours is the shorter housing.

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I may be missing something, but, why waste you time and money on this truck. Put that time and money into replacing the engine in your El K. SBC 350's are a dime a dozen and a bolt in replacement for your 305.

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I'm sure it's a C, 2wd model. There's no transfer shift lever visible in the interior shot.

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I may be missing something, but, why waste you time and money on this truck. Put that time and money into replacing the engine in your El K. SBC 350's are a dime a dozen and a bolt in replacement for your 305.

Because I live in Minnesota, and need something to get me through the winter, as my current winter vehicle is on its death bed. I think I can get this truck for about $300 (it's up at auction... So won't know for sure) Plus, if/when the body falls appart, the I6 is a great engine, and I want a manual transmission in my Camino. It's more I'd do it because I'd already have it, than specifically looking for an engine/transmission.

Plus... Look at it! It's a handsome looking truck n.n It kind of speaks to me... I'd rather kill it doing what it was built for, than seeing it get crushed and melted.

What I really want to drop into my Camino is an Olds 350 Diesel. But those don't come around often,especially in working order. (I know all about their problems and such, I'm well informed on their faults) But I think the I6 should just slip in too, the tranny may take some fudging, but the three on the tree shifter would remove a lot of metal fabbing on the floor...

I'm sure it's a C, 2wd model. There's no transfer shift lever visible in the interior shot.

That's what I was thinking, thanks for the confirmation. :3 I didn't know if it would be up on the dash or something goofy, since it has the shifter on the column. Edited by Twilight Fenrir (see edit history)

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The transfer shift will be on the left side of the transmission hump regardless of the transmission though I'm not sure if a 4X4 ever came with a three on the tree.

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It's a C10. K10s were 4-wheel-drive and I don't see any evidence of it being a 4x4.

 

As for running it into the ground, well, I guess that's OK, but as someone mentioned, it's not a great way to source either a daily driver or a new engine for your Elky. One, a lightly loaded 2WD pickup is about the worst possible winter driver I can imagine (cue the stories of going through blizzards with snow tires and a load of sand in the back), and two, that engine is going to feel pretty agricultural in your El Camino, if it even fits because it's a lot taller than whatever was in there originally. It will also be less powerful, have a narrower power band, slower, and will not improve gas mileage because the gears in the differential will be set up for a V8's torque, not a six, so it's going to work pretty hard. And linking that 3-speed with column shift to your El Camino (which, I presume, has an automatic) will be, um, problematic. Are you going to engineer your own shift linkage, because I seriously doubt there's a "kit" for this swap.

 

Not to rain on your plan, but this truck looks to need a good deal of work to be daily driver reliable and I think its engine, while probably bulletproof, is a crappy choice for a donor powertrain in a late-model. Invest the few hundred bucks in a rebuilt 350, put a 2-barrel carb on it, and enjoy the El Camino instead.

 

PS: Olds diesel? Well, you are a glutton for punishment, aren't you? Oldsmobile diesels were terrible when new, they're even worse today, and in a Minnesota winter, I bet it's no better at moving a car than a stack of cinder blocks under the hood.

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The 250 in this truck wasn't known to be too fuel efficient either. I was reading in a Chevy truck forum that they get between 8 and 12 mpgs with 10 mpgs the norm. The $300 initial investment will cost you a lot in no time at all.

You would be better off spending a bit more money and getting something else that'll get better mileage and will last you for a while.

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I hate to be contrary, but, you can find a good running 350 or 400 SBC for a couple hundred. I have 69 truck 350 in my garage right now that I would take a C note for. Find a 350 and take a can of gas and a battery and fire it up and hear it run before buying. Get all your tools, and maybe a helper, lined up and the engine swap would be a two day, three day at most, job.

 

I had a 78 Olds with the diesel engine. Worst GM engine to ever come down the pike. By 70,000 miles it was junk. Almost impossible to fire off in the winter here in Oklahoma, where winter is like summer in Minnesota, even with the factory engine heater plugged in overnight.

 

I also had an 81 El K with the metric V8. Probably about same power as the 250 6 cylinder. It was grossly under powered. Would top out at about 60 MPH when fully loaded.

 

Listen to the guys on this forum and forget about the pickup.

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Basic reactions:

Until the 1973 model year, all Chevy/GMC light trucks were built as two wheel drive and then sent to a converstion shop for the change to 4wd, which is why they were not that prevalent back then.  What you have is definitely a "C" rather than a "K".

 

The 250 cid 6-cylinder was a 1/2ton engine ONLY.  292s were in 3/4 and 1ton models ONLY.  I drove a '76 C10 1/2 ton, 3-speed, 3.73 rear axle ratio and it averaged 14mph no matter what, including freeway driving at 65mph.  But the similar V8s were worse!  Now, that 6 had enough low end power, with the overal gear ratio in 1st gear, to really leave a red light "nicely", but once out of low gear, things happened more as you might suspect.

 

The 250 is a "modern" designed 6, with some internals which were also V8 items, so it should be smooth and quiet compared to earlier 235s, but it's not a power monster by any means.  Some people didn't need a V8, for whatever reason, but the only real economy is in maintenance (6 spark plugs vs 8, less expensive air filter element, etc.).

 

NOW, what you have is a "survivor" that can be made into a reasonably nice truck, but nothing to write home about.  It can be good basic transportation with a little work, though.  Nothing high-tech by any means!  PLUS almost everything you might need should be available through many aftermarket vendors (LMC, NPD, Classic Industries, etc.).

 

Upgrades?  First would be for electronic ignition, whether adding a GM HEI for a '75-79 era 250 6-cylinder or via an aftermarket vendor (as Pertronix).  Then some Borg-Warner magnetic suppression plug wires and NGK Iridium spark plugs with the correct gap for the HEI use (probably .040" gap would work well).  These changes would make the ignition "set it and forget it" in nature. 

 

The carb is what it is and no more.  Changing it will take a good bit of time and money to get it right.  In the early 1980s, a really trick Holley "staged" 2bbl was used as OEM, but it also came with the later "integrated" head (intake manifold cast as a part of the cylinder head).  So you'd need an aftermarket intake to use it.  Really trick, though!

 

For some reason, GM pickups for this era were somewhat notorious for having 3-speed manual transmission shift linkage issues.  Ford and others did not, so it must have been a design issue as it was the base transmission (and designed less-expensively to get to a lower base MSRP price level).  So, rough use could cause issues!

 

Chassis is pretty straight forward.  Drum brakes all the way around, probably 11x2" brakes.  No surprises there.  Those trucks really need a front stabilizer (anti-lean in cornering) bar.  It's a pure bolt-on situation and will make a huge difference in how they drive and handle.  The later '73-chassis bar and brackets fit (only 1/2 bolt hole width difference in the frame brackets from the ones for the '67-'72 models.  We bought a new '69 C10 350 V8 pickup which came with that bar, unusual for the time, and the truck would corner flat even with 1/2 ton of feed in the back . . . "like a car".

 

Wheels will be 6-lug wheels, just as the '73 K10s used.  That means that the popular and good looking 15" Rally Wheels for the '73-'87 1/2 ton pickups will work just fine.  The rear axle "tread width" is only about '60 inches, so that means that rear tire/wheel combinations will rub the inner wheel wells on the rear in some cases.  We had the stock 15x5.5" wheels with P235/75R-15 tires and they would lightly rub in some cases, as the stock tire size would have been (in current size) P215/75R-15. 

 

So far, although much of this stuff can be found in some speed shop catalogs (WITH using discretion in choosing them!), most of it can be sourced from salvage yards, possibly (front sway bar and wheels, notably) or auto supply stores.

 

NOW, adding a V8 where your 6 is, without using the correct V8 motor mount frame brackets, will fit but also cram the V8 distributor right up against the firewall, rather than having a good bit of clearance from the firewall AND puts a good bit more weight on the front end.  That '76 C10 we had at work had the 15x8 Rally Wheels with P235/75R-15 radials and front sway bar.  It was a blast to drive, but needed a "car" ratio 4-speed to really let that 6 shine with the 3.73 rear axle ratio.​

 

I get the impression you'll be venturing off into "new territory" in the purchase of this truck.  It has potential but it just depends upon what your ultimate goals might be.  Reality is that it CAN make a good truck with some general maintenance and things I mentioned above (plugs, wires, and such).  Adding the '73-era Rally wheels (15x7 width) will enhance the looks and such for little money (compared to aftermarket wheels) and front sway bar too.  BUT it's not going to get over about 15mpg average no matter what, if that matters.  Rust repair panels are readily-available, which is good.  Rocker panel rust was somewhat common, even down here in TX, as the trucks aged.  IF you can get the truck for the suspected price, the street value will probably be greater than your investment price, very possibly.  But that 6-cylinder can be a deal-breaker for some, mainly because they aren't aware of how good it can be in normal driving.

 

Just do your due-diligence in checking the truck for mechanical things (engine runs QUIETLY and smoothly, transmission and clutch work "as designed" and quietly, for example).  Separating the mechanical problems from needed maintenance (which you'll do anyway) might have some "gray lines" to consider, though.

 

NTX5467

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I bought a '68 Chevrolet C-10 (1/2 ton) LWB w/ standard transmission in the late '70's, the first  problem I encountered was the gear shift becoming jammed and not being able to get the transmission in gear. I remember took  the truck to the local Chevrolet dealership, and they rebuilt the column. The shift levers @ the transmission have plastic bushings that can wear out. These trucks have a coil spring instead of a rear leaf spring suspension, may have to replace the springs and/or add air shocks.

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The 1967-1972 Chevy pickups and the similar GMC trucks had their own respective lists of "standard equipment", but some standard Chevy items were optional for the GMC and vice versa.

 

For example:  1) Chevys came with a steel bed floor as GMCs came with a wood plank bed floor as their respective std equipment, but a Chevy could have the wood floor as an option as the GMC could have the steel floor as an option -- on the "wide bed" models.  2)  Chevys came with a Chevy/GM 12 bolt rear axle and coil springs as std.  GMCs had a Dana rear axle and rear leaf springs as std.  The Chevy could have the rear leaf springs and Dana axle as an option (tied to the leaf spring option) and the GMCs could have the Chevy rear coil spring and Chevy/GM axle as an option (again, the axle was combined with the rear coil springs).  3)  Some GMCs could have a manual choke rather than the automatic choke?

 

The complete rear leaf spring set-up was a bolt-in situation for the rear coil spring/trailing arm suspension.

 

The Dana rear axle used different rear axle shafts for each of the model years it was used ('72 being the last, which made finding parts somewhat difficult via GM).  This is for the 1/2 ton pickups.

 

C30 Chevys got rear leaf springs as standard, possibly the HD C20s, too?

 

In many cases, the GMC was the "worker" of the pair so it got things (the Dana rear axle and leaf springs on 1/2 tons) which would allow it to work better for the intended customer, including the wood plank load floor.  This was the GMC heritage compared to that of Chevy pickups back then.  If you were a "serious" farmer, you got a GMC for the better engines and heavier-duty components that were specific to GMCs back then.  The Chevy pickups had the "dipper" oiling system and many were manual transmission models (3-speed, that is, rather than the "granny 4-speed" that most GMCs I knew of back then had in them).  The Chevy 1/2 tons were for the "city farmer" who didn't haul very much in the bed, for example.

 

Chevy did have some credible 3/4 and 1-ton models and the 1/2-tons could probably work as well as the GMCs could, but with the "dipper oiling system in the engine", there could be some problems.  The heavier-duty Chevys had a 261 6-cylinder, which might have had a real oil pump in it?

 

One of GMC's "truck" heritage items was their unique engines, not shared with Chevy, prior to the 1967 model year.  From the 1966 model and back, GMC had their own 6-cylinder engines that were also the basis for their over-the-road heavy-duty truck engines.  The 1/2-tons started with a 228, then came a 248, 270, and 302cid inline 6-cylinder, all on the same block casting family (valve covers and oil pans from the 228 would fit a 302, for example).  The 270 was a 1950s hot rod engine for many racers and some found themselves in Chevy cars (replacing the 235s).

 

GMC also had their 4-cycle V-6 engine family, starting at about 345cid (?) and going upward.  In the early 1960s, there were some V-12 versions built, where two engines were grafted together and used a common crankshaft.  Check Google for videos!

 

All of those differences gradually disappeared up to the 1972 model year.  The 1973 light-duty trucks were all new and other than trim items, the Chevys and GMCs had identical powertrains. 

 

NTX5467

Edited by NTX5467 (see edit history)

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