Finally!!! Was able to drive it home from my shop. Still lots of tuning to do. Help

[SuperNathanSunshine]

Today I was finally able to get the hood back on and get my truck out for some tests drives.

Bought the truck on a whim, then decided to paint it. That's when all budget broke loose and I accidentally bought a built motor on eBay. From there, I rebuilt the trans and rebuilt the axle while meticulously putting the whole thing back together.

I'm a professional maintenance mechanic by day, so taking stuff apart and putting it back together better than it was from the factory is my strong suit. Tuning engines isn't. Now I need the kind of help that I can't find locally. Hell I'd pay a guy if I could find a guy.

The major problem with the tune is that I am getting bogging and backfires through the carb under WOT. Regular driving is just fine. Off idle at a stop sign could be better. I'm trying to go slow and ask pros before I bonk something, lots of time and money invested. This is my first vintage engine tuning project and have studied YouTube and the Power Manual, but I'm out of my depth. I have not adjusted the carbs from how they came to me other than to synchronize them at idle and adjust linkage. I set the timing based on a best guess and what it seemed to like with a regular light and timing tape.

The Truck: 1969 C-30, factory chassis-cab, originally NCDOT truck with flat dump installed after it was decommissioned.

Engine: The motor builder is an aircraft mechanic and sent ALL receipts from when he built the motor in 1992. It was crated and never installed. He changed relevant gaskets, lump ported, and re-broke in the motor after storage. I took delivery straight from him. While this motor has been ran on a test stand and on a few short test drives, it's never been road tuned. Chevy 292 L6, .030" over with stock pistons, HMV-272 cam, lump port, twin Holley 2-barrels on a Clifford maniflold (water heated), Tube headers, GM HEI.

Drivetrain:SM-465 Trans. GM 14 Bolt rear with 3.73 gears.

Timing: 18° base, 12° vacuum, 36° total measured with timing tape.

Some Pics

[CG]

Sorry SNS, we are going to need a lot more pics of this truck from beginning till now. I love it! I cant help you with your tune, but really, more pics would be awesome.

[SuperNathanSunshine]

Originally Posted by CG

Sorry SNS, we are going to need a lot more pics of this truck from beginning till now. I love it! I cant help you with your tune, but really, more pics would be awesome.

As requested

[CG]

Nice work! I have a 71 C30 Ive been putzing around with. Busy with a lot of other things at the moment though so it just sits in the garage.

[Sheepdip]

That's a pretty sharp looking C30 Dually. I see you upgraded to a 14 bolt rear diff. I'm assuming you upgraded the front to disc also? Looking Good!

[toms68cst]

Wow, Sweet truck. I really like the chrome wheels on a 1 tonner.

Hope you get it sorted out so you can show it off.

[wesmigletz]

How is your pump shot? Are you getting fuel the instance the carb is cracked open? An intake valve too tight (rocker holding valve open)?

[AU Doc]

Originally Posted by wesmigletz

How is your pump shot? Are you getting fuel the instance the carb is cracked open? An intake valve too tight (rocker holding valve open)?

Accelerator pump and valve lash were my first thoughts as well.

[j_cst_10]

I would recommend buying some simple tools if you don't already.

1. Adjustable timing light
2. large face vacuum gauge for diagnostic purposes

Whatever it is, I am sure it simple... However simple is a relative term. You need to understand what is going on first in order to diagnose an issue.

The accelerator pump is a good tip, make sure you are getting a squirt instantly.

A lot of times with a bog or hesitation on WOT it turns out there is a vacuum leak somewhere. Someone left a plug off the carb or there is a problem with a carb or intale gasket.

['68OrangeSunshine]

Ambitious project. What carbs and what CFM are they?
I have a 292 L6 bored .030 over, Crane 260H cam, 1.84'' intake valves, HEI, Offy intake Clifford headers and an Edelbrock 1404 500 CFM cam.
292 @ .030 over = 296 CI.

[specialtyretail]

That truck is just too cool.....

[LockDoc]

Originally Posted by SuperNathanSunshine

As requested

All I get when I go to that site is a black screen.

LockDoc

[kev2809]

Originally Posted by LockDoc

All I get when I go to that site is a black screen.

LockDoc

https://m.imgur.com/a/QiLU37f

try that?

[LockDoc]

Originally Posted by kev2809

https://m.imgur.com/a/QiLU37f

try that?

Same thing with that link. I wonder if my Malwarebytes is blocking it. Dunno'

LockDoc