99 350 Vortec Timing

What is the timing degs. for my Sub.
Changed the intake gaskets, thought I had dist. back in correctly, but had it checked at a local garage. They said it was at 4deg. adv. and changed it to 0'.
Is this correct?
Seemed to run great before! Now it seems a little doggie.

Thanks Roger

What is the timing degs. for my Sub.
Changed the intake gaskets, thought I had dist. back in correctly, but had it checked at a local garage. They said it was at 4deg. adv. and changed it to 0'.
Is this correct?
Seemed to run great before! Now it seems a little doggie.

Thanks Roger


Zero degrees is right on the money. The spec is zero degrees plus or minus two degrees so anything from -2 to +2 degrees is good.

Not adjusable,the computer does the timing.There is a camshaft postion sensor inside the distribitor.The emissions label should say timing is not adjustable.If you mess with the timing,service engine light will come on and it will be a camshaft position sensor code.

Thanks Thunderbolt, maybe it's just me not used to driving it! We have 6 vehicles...

Not adjusable,the computer does the timing.There is a camshaft postion sensor inside the distribitor.The emissions label should say timing is not adjustable.If you mess with the timing,service engine light will come on and it will be a camshaft position sensor code.

Yes,wafrederick, I read the label.
But when you remove the dist. you must replace it the way it was and set timing using the tech anylizer, which taps into your comp. telling you where your timing is at ! Then follow procedure on tech... loosen dist. and set while running.
So, reality. It is adjustable. If you can afford the equipment to do these things, that keeps getting outdated with the newer vehicles.

No, it is not adjustable.The hold down clamp does not come off.

You can adjust the base timing on the 96 and newer 305 and 350's on the V6 it is a different set up and not adjustable

No, it is not adjustable.The hold down clamp does not come off.

It most certainly is adjustable !!! You have to have a diagnotic scanner to set it. You must have never worked on one if you say the hold down doesn't come off. How do you think you get the distributor out and do the intake gasket. It is not adjustable with a timing light, But it is adjustable. I have done several of them and you are correct about the computer controlling the timing, But in order for it to do that correctly the engine must have a base timing of between -2 and +2 degrees. The distributor has to be installed and set to TDC because while the computer controls when it fires it cannot move the distributor if it is way off. I don't know about the V-6, But if the distributor is removable there must be an index mark or something to get the rotor close to number one at TDC or they are distributor less. I have never worked on a V-6 vortec.

Thunderbolt, on the V6 distributor the hold down is part of the distributor(one piece) and doesn't have a slotted hole to allow adjustments, the base timing spec is pretty wide to, +/- 15 degrees or more

Thunderbolt, on the V6 distributor the hold down is part of the distributor(one piece) and doesn't have a slotted hole to allow adjustments, the base timing spec is pretty wide to, +/- 15 degrees or more


Thanks for the info Jeremy !! I didn't know that because I have never worked on the V-6. After I thought about it I have seen a few other engines like that where you line the rotor up with number 1 and the distributor locks into a slot and the computer does the rest.