[msgdsrf]

Originally Posted by davepl

Whoa, let's back up a bit. It probably is fine just as you say but you can't measure idle advance with the vacuum line connected. You can, of course, it just doesn't tell you much.

Cap it and set it like the factory tells you. I'm going to guess you need 12 degrees of initial advance. Regardless, figure out where your best idle is, set it there, and then get the distributor recurved limit total advance to 35 or so (or whatever is reportedly best for your motor, presuming no dyno is handy).

A lot of people crank the initial timing ahead and forget that the mechanical is still going to add what it thought it needed from the OLD base timing. So if you had 6 base and 29 centrifugal for a total of 35, now you'd have 12+29 for a total of 41 and it'd be just too much. Probably ping at part throttle with vacuum advance too.

All of this depends on the fact that everything else is right. You can compensate for a vacuum leak by cranking the timing ahead, but it doesn't fix it. So everything else has to be right too.

He was just asking if 25 was within range (with vac.) It is.