trying to set timing once and for all., w/ crane unit harder than i thought Options

[xsboost90]

ok, so the other day i figured out that my optic eye in the distributor for my xr700 was set too far clockwise making the timing extremely retarded.. (IMG:http://www.914world.com/bbs2/html/emoticons/laugh.gif) go ahead...

tonite i decided to set the timing, but found if i set it to the stock setting, the car was detonating and idle was very poor as well as performance. I set it back to where it idled best, had best throttle response and stopped detonating, and it is...according to the timing light-yes w/ hose off at 3500rpm- about 20degrees advanced. Im thinking maybe the timing is advanced but the optic is still off making up for the difference, anyone had this problem? This is a real pain in the ass since my timing marks are useless now.