I tried to advance the timing on my 92 GT and I had problems seeing the timing mark on the crank pulley, so what I decided to do was go around that. I have an MSD 6A (not installed yet) ign. box, well MSD makes an adjustable timing control that plugs in with your MSD ign. This will give you the ability to advance/retard your timing from the inside of your car, this way if you don´t feel or can´t afford the expensive gas you just have a simple turn of a knob and your good to go. The adjustable timing control part # from Jegs is 121-8680. I should have all this done by next week. I am also removing all air conditioning components and relocating the battery to the trunk. When I am done I will post how it all went.