I've been reading over articles, but I'm still confused. I found the groove, marked it with white out, then shot it with the strobe gun. My grid plate sits at about 2 O'clock and my "uncles guess" had the line around 12:30. Vacuum hose was unplugged. My question is, about where should I have the mark positioned?

Sorry if this is a stupid question...but I have to ask lol.

 

Since we don't know that kind of engine you're talking about, the static timing for most stock engines is set between 6 and 10 degrees before top dead center.
If it won't idle there, make sure it doesn't have the wrong balancer installed.
If it is an 8" balancer it could be one that goes with this timing pointer:

Edit: 1980 350 2 bolt main shown with 12:15 timing mark. Original color:blue.

 

If the balancer is correct and the tab is like the one shown below, the second peak above the big valley is 8° before top dead center.
The little valley above the second peak is 10° and the little valley just below the second peak is 6°.
The correct setting should be on a label under the hood or in a service manual.

Edit: 1988 350 TPI engine shown with 1:30 timing mark. Original color: black.

 

Not a stupid question at all really... pretty good, actually, considering that most people who ask this same question about this same situation don't notice the amount of detail that you did. We usually have to wring it out of them, painfuly, step by step, with a bunch of "I thought" and "I heard" and "But why" and every other kind of argument you can imagine, all thrown in to make the process as difficult as possible.

1. Your uncle is approximately correct: with the stock crank damper, and the car set up for checking the timing (big flat plug with about 4 or 5 wires in it that hangs down from the base of the carb unplugged), the balancer mark will show up between 12:00 and 12:30.

2. You didn't tell us this, but you gave enough info to where it's obvious, that you have an aftermarket bolt-on timing tab.

3. There are NO AFTERMARKET TIMING TABS WHATSEOVER that support this. Why, I can't begin to imagine; that's only been the stock place for the last 20 years or more, so you'd think some one of them, just one maybe even, would have noticed it and come up with a part to fit; but no. EVERY SINGLE ONE of the aftermarket ones you can buy, ONLY supports the old 70s and earlier mark, which is at about 1:30; like Supervisor's pic, which looks to me like an early 70s 350.

4. The only thing you can do is to locate TDC as accurately as possible, with a piston stop and/or a dial indicator, by DIRECTLY OBSERVING the #1 piston itself. Then, make yourself a NEW mark on your balancer, that lines up with your aftermarket tab.

 

My timing tab actually looks the same the timing tab on that 88 350. Actually, I'm willing to bet that it is the same as mine...

When I bought the car I was "told" it has a bigger cam in it. It does seem to have alot more kick than my other 350...but I have no idea what size the cam is. So I'm not really sure what to set the timing it. It seems that my timing was too advanced, so I rolled the base timing back to about 14 degrees. Sounds really really close. I'm not getting any delay when I step on the gas, but it seems abit retarded. I also now notice a "shake" after I turn the car off after retiming. I do have to admit that it drives alot better now.

I was guessing that my base timing is about 14 degrees, and I guess 14 more when on the gas, and about 20 of vacuum. Am I in the ballpark?

 

It depends on the cam and combustion chamber shape. If it's a non-stock cam, the stock timing spec goes out the window.
My cam has a lot of overlap and won't even idle close to the stock setting. The initial is set at 15°, with it idling and the vacuum advance plugged in (unported) it's at 26°. And this still isn't enough.
BTW, this setting would destroy a stock engine in a short time.
If it's a non-stock cam, you just have to find out what it "likes".
That's why there are so many posts on "tuning"...

 

So I do have a different cam? It is really strong with a initial set of 14. After driving some it is a touch on the retarded side but maybe a couple of degrees off. Before, by hand it was running around 20 when done by hand. Seemed to be too much advance...hesitation in when hitting the gas.

What is the stock initial setting?...just curious.

 

Need to know what engine is in it.
For example:
87 350 TPI set on 6° BTDC.
87 305 4bbl set on 0°
No 350 with a carb in '87.

 

Originally 87 350 TPI, converted it over to a holly 4160 750 cfm carb with an Edelbrock performer manifold for the 87 heads.

Seems to be running really well at 14 BTDC...looks to be the sweet spot after a bunch of driving today. It was running weird around 20 BTDC...was set by hand (gas delay...engine slightly missing)...and I'm scared to even drive it below 10. I've double checked, timing tab setup is stock. About what cam are we talking here?