GM-GMC: timeing on 1996 4.3 GMC truck, compression stroke, gmc truck

Question
I took out disturibitor and failed to mark what way rotor was sitting. How do I set dist. To right position to get timeing right. I bring up to TDC and it will not start unless I move dist. Back a few teeth then it will not idle right and misses like it is lugging motor down and I have to gear down to get up small incline. I need my truck and can not get dist. Set can you please help me! Thank you so very much.

Answer
You cannot. If you think you are having a timing issue, you can check by removing Cyl #1 spark plug, then, while keeping your thumb covering the #1 Cyl spark plug hole, rotate the crankshaft to TDC (top dead center) on the compression stroke. Pull the Distributor cap, the rotor should be pointing to a small > at about 8 oclock on the edge of the distributor. There should be a small 6 in the > as you have a V6. I hope that helps.

when you do this it should reset itself back to factory default when you crank it.