Hi!
I'm trying to set the ignition timing on my 1970 Cadillac. My Chilton book says it should be set to 8 B.T.D.C.
My question is how do I know which timing mark is 8 B.T.D.C.?
I see 3 marks but I can't find any other indication... How can I know which mark is TDC and what the scale is? :hmm:
Here's a picture of the timing marks on my car :
http://www.vif.com/users/mordark/dulcydrama/timing_marks.jpg

Thank you!

you will have to clean the rust off that tab to see the lines/marks and numbers, or, the tab may be too rusty find any marks.

I believe the first line is 0 degrees the second line is 5 degrees and the third line is 10 degrees

According to the '70 shop manual it should be set at 7.5 degrees which is half way between the left and center notches (looking in from the front). It should be set in drive with the advance and parking brake vacuum lines plugged and at 600 rpms.