Join Date: Mar 2002
Location: Austin, TX, USA
Your explaination is correct. It's nice to have one of those timing lights with the offset knob on the back. That way when you rev it up, you can crank the knob until the timing marks line up on 0deg and read the timing off the back of the timing light. Only thing is, some of those timing lights are a bit inacurate. But that's usually Ok since you aren't shooting for precice numbers, but rather getting all the timing you can get without causing detonation.
As for 92 octane at 11:1 compression, you'll have to be ever aware of pinging and detonation. As a result, you'll want to sneak up on the timing values for your car. For example, start with the heaviest advance weight springs. Take it for a drive. If you don't hear any pining, replace one of the springs with the next lighter spring. Drive it again, and if you still have no pining, replace the other heavy spring with a lighter one and so on. When you encounter pining, back up one setting on the springs.
Vacuum advance adjustment is similar, but must be done while driving the car with a load on it.
Also, If you find that your destributor advances too much, look for ways to limit the advance. Some weight kits will limit the total advance. I knew a guy who drilled the advance plate installed stops to limit the advance.
Crane sells a little star wheel that mounts on the vacuum advance canistor mounting screw. It's purpose is to limit the amount of vacuum advance. But what it really does is set the baseline position for advance. This makes it necessary to reset base timing and ultimately ends up knocking off a few degrees on your overall timing. That's the method I am using.
68 Coupe, 350 w/ Edelbrock Performer RPM heads, cam, intake, 700R4, Dave's small body HEI