MSD distributor tuning

gliderider06 said

Anything over 15* initial the thing will ping when hot when giving it a slight push on the throttle. I'm using autolite 64 plugs. It helps reduce the detonation.

Click to expand...

And there is another clue. Measure and plot that timing curve. Mark it in red starting the rpm it will ping with light throttle if that was done without vacuum advance. Mark it in orange something like that if it was with vacuum advance. Then go check vacuum advance so you know the actual timing when the pinging occured.

As far as the carb, it mostly will change the AFR. AFR and Timing are related. Leaner less dense conditions need more advance because the burns tend to be slower.

Generally best to set timing, then work on fuel mixtures. Repeat until you can't get closer or don't care to get closer for all conditions.

Timing has to be set for hot engine conditions - unless you are drag racing only