What does it mean to advance/bump up the timing, and where and how do you do this? Ive heard people doing it themselves

 

Search on here how. Google can also help you. If I wasn't on my phone id link you some threads.

 

By the distributor is a grey connector called the spout. By unplugging that the computer stops controlling the timing. Then you can rotate the distributor and reset the timing.
Using a timing light you mark the balancer at 12 or 14 degrees then turn dist until the mark ligns up with your mark. Then you tighten up dist and plug in spout and your done. Keep reading on here. You'll find pics and better write up for sure.

 

Oh....
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Very helpful when asking questions and such

 

It's the ignition timing, which is the number of degrees of crankshaft rotation before the piston is all the way at the top (called top dead center or TDC) at which the spark plug fires.

On your truck (assuming it's the 1989 in your profile), it is adjusted using a timing light and by loosening the clamp at the base of the distributor, and then slightly rotating the distributor. There is a connector jumper (called SPROUT) that needs to be removed before checking the "base" timing.

Here's a good link:

Fuel Injection Technical Library » Setting the timing

Now, if your truck is anything like mine, the distributor may be frozen in place, you can search on that as well and read all about it too.

 

Recently did this on my 460, Made a noticable difference. Very pleased. Also my "spout" was on the drivers side fenderwell

 

Yup. Remote mounted tfi modules have the spout moved as well.