IML: A technical question about manifold air leaks and pinging!

I am finally able to drive my car farther than the video store, and now I have a problem thats kickin my butt. A couple of years ago I put pertronix ignition on my car. It has never went very far, because of my brakes until recently. I notice now I have a pinging. It used to be very bad, and I regapped the plugs an extra .005 of an inch and it cut the noise in half. I have retarded the timing another 5 degrees and That also helped alot. But I still have ping. I went up 2 sizes in metering rod springs. no change. It seems to do it when its warmed up a lot. I disconnected and plugged the line into the brake booster to see if that was the culprit. I had my tach and timing light on it, watching intently, and then I noticed something strange. the car had been running now for about 5 minutes, after a couple more minutes, I saw the RPMs start to go up slightly, about 100-150 RPMs. STRANGE! I sprayed a little starter fluid over the carb, and it acted like it wanted to die. Not exactly what I was expecting, but I know how the car will act if it gets ether spay sucked in. I started spraying around the intake manifold and the base of the carb. I have it pin pointed to 2 spots where the car wants to die when I spray the ether. One on the base of the carb and the other on intake manifold. Will a vacuum leak like this cause my car to ping as it gets warm, especially hard throttle and going up hills???? I really need some good insight on this.

Just to answer the obvious questions first- I am using 91 octane with 104 Octane booster, The engine was rebuilt about 3 1/2 years ago, the vacuum advance seems to work, and I am using Autolite 75 plugs. (the only difference according to parts man between these and 85 is that one is resistance and one is not, I guess it affects radios and computers). Any help or answer to my questions are greatly appreciated.