I had a tune up done a couple years ago and the shop set the timing advance on the 455 at 4 btdc when by the sticker it's supposed to be 10. At least it was 4 when I checked last week. Back then they said they didn't want it to ping on today's crappy gas so they backed it off some. My question is, since I only run her on 92 octane non ethanol super with lead substitute is that really necessary? Can I advance it to 10 and be okay? Also, do you turn clockwise or counter clockwise to advance on the 455?

 

Clockwise to advance. You could try bumping it up a couple of degrees and see what happens.

 

As Bill said, clockwise to advance, Also, as points wear timing retards by a few degrees. I believe your engine should be 8* btdc.

 

Cool, thank you! I'll try it this weekend.