V6 engine question

[Lou Boffa]

Guys, can you all tell me about the V6 that would have been original in a '69 C10? I havent heard or read anything about these motors. Owner says its original to the truck. Thanks

[geezer#99]

Look here for info.
http://6066gmcguy.com/

[Xeen]

As far as I know it's an inline 6 not a v6.
Unfortunately I don't know a lot about them except that the 250 cubic inch I6 came as the standard engine with the 292 cubic inch I6 as an option.

[Lou Boffa]

Originally Posted by Xeen

As far as I know it's an inline 6 not a v6.
Unfortunately I don't know a lot about them except that the 250 cubic inch I6 came as the standard engine with the 292 cubic inch I6 as an option.

They insist its a '69 Chevy C10 and has a V6. Its a couple of hours away, but its got my interest.

[Xeen]

Originally Posted by Lou Boffa

They insist its a '69 Chevy C10 and has a V6. Its a couple of hours away, but its got my interest.

Here are all the engines available from 1967-72, so if it has a v6 installed it isn't factory original.

250 cu in (4.1 L) I6
292 cu in (4.8 L) I6
283 cu in (4.6 L) V8
307 cu in (5.0 L) V8
327 cu in (5.4 L) V8
350 cu in (5.7 L) V8
396 cu in (6.5 L) V8
402 cu in (6.6 L) V8

I will say this though, If it really is a factory installed v6 then it is a special order and it's a unicorn but I would only believe it if it is listed on the SPID sticker inside the glove box door.

[Lou Boffa]

[QUOTE=Xeen;7266751]Here are all the engines available from 1967-72, so if it has a v6 installed it isn't factory original

Im going to have to go see it. I read where GMC had a V6 in its pick ups, but I dont find where Chevy did. Curious.
Thanks for the info.
Lou

[michael bustamante]

GMC had the 305 v6. cool looking motor
chevy did not come with a v6

[geezer#99]

Maybe it's a gmc with chevy front sheet metal!
Lots of guys did that because they didn't like the quad headlight look.
Or that's all they could find for a replacement after a wreck.

[factorystock]

Originally Posted by Lou Boffa

Owner says its original to the truck.

Is the engine listed on the SPID? The 305 V6 was used in GMC's, so it is very possible it was a "SPECIAL ORDER" on the Chevy. We have seen instances were rear leaf springs were "SPECIAL ORDERED" on '67 2WD Chevy C10 and C20 pickups.

[too much stuff]

The V-6 was a gmc thing used through 1969. Not available in chevy as far as i know.

['68OrangeSunshine]

The tell would be in the VIN:
CS = L6
CM =V6
CE = V8

[Boog]

I remember the late 60's GMC V6. It sounded nothing like an L6. As I recall they were big on torque.

[mikess396]

This old girl runs great

[Lou Boffa]

Thanks guys. I'll just have to go and see. Were they decent motors? Any quirks or performance issues? The V6 I had in an '85 Scottsdale was definitely "torquey."

[geezer#99]

Low rpm torque monsters!!
Carb can be a problem.
Easy to swap to a holley 2bbl though.
A unique motor. Some came with plaid painted valve covers!

[Stocker]

Anecdotal at best.... from back in the day, they were said to be great for low-rpm torque, not so much for horsepower, and quite thirsty. This from an era when 30-something cents per gallon was normal.

['68OrangeSunshine]

By all accounts, they were real stump-pullers. Total torque monsters. Both the 305 and 351 V6s were serious work truck motors.
If there is a drawback, it would be the fact that there are no aftermarket or Hi Perf parts for those engines. As I understand, it's even hard to get stock rebuild parts for the GMC V6s. Since they seem to last forever, nobody needed to fix them much, so supply/demand was weak.
TJ has a 305E post on the Engine and Driveline forum. He seems to know something about hodrodding the GMC V6s.

[Xeen]

LOL I think that picture speaks for itself, it looks like it has been sitting on the bottom of a lake for 25 years and it still runs like it's new, now that's good engineering!

[1972RedNeck]

Originally Posted by Lou Boffa

The V6 I had in an '85 Scottsdale was definitely "torquey."

Not even close to the same engine.

Up through about half of '69, both the 305 and 351E V6's were available in GMC's. They were advertised to run 200,000 miles in a heavy duty truck with no major overhaul. They were super tough and had lots of torque. As for economy, they aren't bad in a pickup.

If it doesn't have enough power, a 478M will bolt in place

[GRX]

Built a few of those GMC v-6 back in the day. Started out as a diesel design if memory serves. Having 4-ring pistons would seem to support that. General consensus on them is they are heavy, poor power to weight ratio gas guzzling low RPM engines with little to no aftermarket parts available. Despite all that, great for coolness and rarity factor. If that is your goal.

[edit] - The spark plugs sit upright. Be sure to blow out the area well with compressed air before removing the plugs. Dirt & crud dropping into the cylinders was the demise of many of those big v-6 for sure.

[alsriv2]

Had a girl friend up in Maine way back when whose Dad had a '69 C20 with the GMC V-6 engine/automatic transmission combo in it. Didn't know a thing about SPIDS back then, but that truck was white with a Red interior.
Engine was original to the truck, so based on comments here, I would suspect the V-6 might have been a "not well known" option for the Chevy line back then.

[Lou Boffa]

Originally Posted by GRX

Built a few of those GMC v-6 back in the day. Started out as a diesel design if memory serves. Having 4-ring pistons would seem to support that. General consensus on them is they are heavy, poor power to weight ratio gas guzzling low RPM engines with little to no aftermarket parts available. Despite all that, great for coolness and rarity factor. If that is your goal.

[edit] - The spark plugs sit upright. Be sure to blow out the area well with compressed air before removing the plugs. Dirt & crud dropping into the cylinders was the demise of many of those big v-6 for sure.

Thanks much. Heading up tomorrow to check it out. Should be interesting.

[factorystock]

V6's were designed to have similar characteristics and qualities as diesel engines, high torque at low rpms and long intervals between overhauls. The higher the cubic inch of the V6 ( say 401 or 478 ), the better the performance ( 351 was the largest in pickups). This is why they weigh so much.

[swamp rat]

I was watching a vid on youtube one day and the guy was talking about these V6's he said one of the biggest problems that people made the mistake of doing was removing too much valve lash when adjusting the valves, i think it was adjusting them cold and not hot, then when the engine warmed up it was low on power, said he bought a number of truck with the engine and after readjusting the valve lash most had more power than when he bought them.

Anyway i had a 60 GMC with the 305 and he had plenty enough power and torque, later on i sold the truck to a high school buddy and he wasted no time to light up the tires and make a smoke show...

[Ol Blue K20]

One thing no one has mentioned, I've seen some ads that say V6. They show a pic of a straight 6 and it's just because they don't know any different.