Looking for an original lubricant list '69

[Afishinado]

My '69 C/10 has not had a full service since I bought it two years ago. It spends the whole winter in the garage, battery disconnected, and goes approximately 10 miles a day in the summer. I want to change the fluids, and I do not want to go synthetic as I think it will cause it to leak more. It has the 292 with a 3spd+granny gear and a 4:11 positraction diff. I just ordered the manual off ebay, but maybe someone has one handy and you can tell me what the manual recommends.
Any help appreciated!

['68OrangeSunshine]

Originally Posted by Afishinado

My '69 C/10 has not had a full service since I bought it two years ago. It spends the whole winter in the garage, battery disconnected, and goes approximately 10 miles a day in the summer. I want to change the fluids, and I do not want to go synthetic as I think it will cause it to leak more. It has the 292 with a 3spd+granny gear and a 4:11 positraction diff. I just ordered the manual off ebay, but maybe someone has one handy and you can tell me what the manual recommends.
Any help appreciated!

292....SAE 30 or 20W-50 -- I like Valvoline Racing VR1. It already has the right ZDDP levels. Six quarts with new oil filter.
[You're right about synthetic. I ran Synpower in the 350 on my '71 GMC Jimmy and it leaks bad.]

SM465....90 weight or 80W-140 [if you live in the desert] GL-4. The bronze synchros do not like the limited slip additives in GL-5.

12 Bolt Corporation Rear with Posi.....Same or greater viscosity as the Transmission, but you want GL-5. If you can find GM Limited Slip Additive, pour the whole 4 - 6 oz tube in first.

On both, fill until oil starts dribbling out of the fill port. Then re-cap.

[jumpsoffrock]

^^It's like your ear tingles every time someone starts talkin' about a 292....lol

[HotWheelsFan]

Gotta love that big six

[67 twins]

Originally Posted by HotWheelsFan

Gotta love that big six

I know I do!

[Afishinado]

68OrangeSunshine, you nailed it. After about 6 hours researching I agree with all you recommended. I bought trans oil from Summit, rear oil from Amsoil, and motor oil off Amazon

Originally Posted by HotWheelsFan

Gotta love that big six

Agreed.... I only knew one guy that didn't like his 292, of all people, my father.
His brand new '65 C/10... When he was ordering it (I was in 7th grade) and I was pushing him hard to get the 283. He was adamant,I remember it like it was yesterday "I don't need to feed eight mouths, six eat enough as it is" Fast forward a few months, we were out hunting and he was telling his bud the 292 was a mistake, it had tons of power, but but couldn't pass a gas station. He was coming from a '54 with the 235 ... Fast forward 60 some years, I finally agree with him, it has big balls, but requires a lot of fuel. Since mine only goes about 12 miles a day, and is stored all winter in SD, it don't matter much. I have fallen in love with that familiar old sound, bone stock, with stock exhaust. Here's a picture of it doing light duty pickup work. BTW, after being on a wait list to get it into the shop to do some minor rust repairs (by most standards around here) and a fresh coat of paint. I have decided to leave her just the way she is, after dropping the $23k+ it would own me (and I still need to redo the interior). She's a 'attention ho' as she is... But I have a '23 Equinox at my Florida house I won't need this winter. I'm thinking of selling it and finding another 67-72 C/10 to replace it.

My baby...

[notsolo]

Great truck, I know you wouldn't want to change it, but a rear gear swap would improve the gas mileage and the highway driving.

[68bowtie]

I would NOT paint that truck. It’s beautiful as-is. Rust repair sure, then touch it up. I love original orange paint, not very common…

['68OrangeSunshine]

Originally Posted by jumpsoffrock

^^It's like your ear tingles every time someone starts talkin' about a 292....lol

True story.

['68OrangeSunshine]

Originally Posted by notsolo

Great truck, I know you wouldn't want to change it, but a rear gear swap would improve the gas mileage and the highway driving.

I agree. My '68 C/10 Orange Stepside came with an L25 292 L6, SM465 4-Speed and 3.73:1 12-Bolt rear. I added Posi later.
It also came with 7.00 x 17.5 tires on 17.5 x 5.25 6-lug rims. Those rims are obsolete. Mine were shot about 100,000 miles ago.
Currently, I run 235/85/R16 Cooper Discoverors on 7 x 16 white spoke rims. Tall and narrow profile helps with mileage.

['68OrangeSunshine]

Originally Posted by Afishinado

68OrangeSunshine, you nailed it. After about 6 hours researching I agree with all you recommended. I bought trans oil from Summit, rear oil from Amsoil, and motor oil off Amazon



Agreed.... I only knew one guy that didn't like his 292, of all people, my father.
His brand new '65 C/10... When he was ordering it (I was in 7th grade) and I was pushing him hard to get the 283. He was adamant,I remember it like it was yesterday "I don't need to feed eight mouths, six eat enough as it is" Fast forward a few months, we were out hunting and he was telling his bud the 292 was a mistake, it had tons of power, but but couldn't pass a gas station. He was coming from a '54 with the 235 ... Fast forward 60 some years, I finally agree with him, it has big balls, but requires a lot of fuel. Since mine only goes about 12 miles a day, and is stored all winter in SD, it don't matter much. I have fallen in love with that familiar old sound, bone stock, with stock exhaust. Here's a picture of it doing light duty pickup work. BTW, after being on a wait list to get it into the shop to do some minor rust repairs (by most standards around here) and a fresh coat of paint. I have decided to leave her just the way she is, after dropping the $23k+ it would own me (and I still need to redo the interior). She's a 'attention ho' as she is... But I have a '23 Equinox at my Florida house I won't need this winter. I'm thinking of selling it and finding another 67-72 C/10 to replace it.

My baby...

Thanks, I've been running my Orange Stepside since I was 23. That was 50 years ago. So I know my lube chart by heart.
405,000 Miles on my odometer.
I rebuilt a 292 in 1977 -- ran it 250,000 miles. Took 25 years. Rebuilt the original L25 block in 2002. On the road in 2005. Engine's in great shape.
I got T-Boned in April 2022. Crushed my passenger side rear fender. KO'ed my 12-Bolt rear end. Bent Trailing Arms. Warped my rear wheel.
So after getting another rear carrier rebuilt with fresh axles and 3.73 differential, and swapping a good used pair of Trailing Arms [w/new bushings]. Plus new rim. I got it back on the road. Now I find excessive vibrations over 60 MPH.
A brake shop found that my Propshaft was bent, or dinged in. So that's my next project.
Also it crabs left. Frame straightening or rear end alignment may be in order.

True. The 292 is no fuel economy queen. It is the Big Block of the L6s. But 12 MPG is double the mileage I used to get with a BBC 454 stuffed into a '67 K/10 Suburban. ''White Fang'' got 6 City, and 8 Highway.