Truck Repair: GMC 1500 1990 350 timing sierra 4x4 single cab, sierra 4x4, gas milage

Question
with the EST disconected. what notch should the timing light flash on to be set right?             Also I have been haveing trouble finding out for sure what my pluges are supposed to be set at . the stiker says 35 and the book and parts houses say 45. I tryed 45 and it runs real rough at 35 it seems to be a lot better. and what pluge would you recomend for the best performance and gas milage.  thanks steve.

Answer
Hi Steve,
Use information on the label under the hood, whenever it is different from a manual.
With the timing est bypassed, lign up the mark that the label says to time it to, with the mark.
I like to use the plugs shown on the sticker, set at what the sticker says.
Good luck,
Van