This morning I believe I successfully set the timing on my inline six to 14btdc. I guess I was over thinking things a bit before with my fancy timing light, but its actually really simple to do. Anyway, figured I'd post the process for anyone else who's curious. Let me know if I've gotten anything wrong.
First off, you need a few tools:
-An inductive timing light (you can rent one from the auto parts store)
-1/2 inch wrench
-something that will make a small bright mark (white out, silver sharpie, nail polish)
First, crawl underneath you truck (in park or gear with the e-brake on and can't roll anywhere).
Clean up the metal part of the crank pulley to find the little timing mark etching and mark it with white out or something so you can see it really well. Remember that the mark is small and you might have to do some searching to find the mark. When I couldn't find it I cranked the motor to move the pulley around partially. Next clean up the little strip of toothed metal with the timing marks etchings. You can locate these from the top by following the yellow arrow in the first picture, but you've got to get on the ground to clean them.
Your cleaned up marks will look like this (here's where the flashlight comes in handy).
Even cleaned, the marks are really hard to read, so here's an edited pic to help you out.
Now turn your truck on and let it warm up to normal operating temp.
Once youre truck is warm, shut it off. Pull out your spout connector (here's where you can read all about what it does http://www.merkurencyclopedia.com/EEC-IV/spout.html
) PUT IT IN A SAFE PLACE LIKE YOUR POCKET AND DON'T LOSE IT. ON TOP OF YOUR WASHER FLUID RES IS NOT A SAFE PLACE.
Loosen up the distributor bolt just A LITTLE with a few counterclockwise turns. DON'T MOVE YOUR DISTRIBUTOR YET!
Ok, turn the truck back on and hook up your timing light, with the inductive clamp on the first spark plug wire. Strobe the light down between the belt onto the timing marks. If you've done everything right thus far it will strobe on your timing mark on the crank pulley as it passes the plate with the little teeth, and you can figure out what your timing is currently set to. It will look like this (note I was fooling around a little here and the timing in the pic is set to 18BTDC, which is too much for most people).
Now that you know your timing, you can adjust it by very gently nudging the distributor either counter clockwise or clockwise. You only need to bump it a degree at a time, and then strobe the pulley again to see where you're at. Stock timing is 8-10BTDC. If you have done an ignition upgrade then you can bump it up a little like me.
Plug the spout connector back in and you're done! Hope this helps!
For all you guys with 8 cylinders, its essentially the same process, just things might look a little different. Theres great instructions listed here with pics of a 302 http://www.fullsizebronco.com/forum/showthread.php?t=63592