Hey Z people! The Crank turns COUNTER CLOCKWISE right? and if thats the case then the timing marks on the crank pully from left to right would be 0,5,10,15,20. So... the timing pointer will hit the left hand mark first (0 degrees). Just to be clear the 0 degree would be in the 8 o-clock position,

5 degrees would be 9 o-clock, 10 would be 10 o-clock and so on and so on. so the pointer would hit the 8 o-clock(0 degree) timing mark first... NOT the 12 o-clock (20 degree) mark. and isn't 17 degrees of advance the recomeneded timing?

Rock on Z people!:stupid:

You're correct that the engine turns clockwise when you are looking at it from in front of the car. However, the timing marks are reversed from the way you described them. Remember, the marks are referenced to BEFORE top dead center. Hence the bigger number is what the timing mark comes to FIRST.

As for how much advance to have at idle, there is much discussion on this, especially depending on how you may have modified your car. For my '73 w/L28 and carbs and mild cam, header, etc., I find I can go about 12-14 degrees advance at idle without pinging using premium fuel. That gives me about 36 degrees of total advance as measured at revs above 4k with a timing light. That's at 6000 ft elevation. I also found I could advance a few more degrees on cool days, but that would lead to pinging on the really hot ones. Since I'm sure I can't accurately hear the onset of pinging until it's quite severe, I backed it off a few degrees to be safe. I doubt your situation is the same as mine so you'd have to experiment.

I think the factory spec is 8 degrees FWIW.

wait... if I'm facing the front of the engine is the crank turning COUNTER clockwise or just Clockwise? I understand the timing marks now but which way s the crank turning?

Clockwise.