definately better to try some higher octane fuel first.... try gapping the plugs a hair wider too, the pertronix should be able to do it if you have a flamethrower coil to go along with it..... might clean up your driving a bit.... other than that you can try to back off the timing just a degree or two, that much wont hurt performance much... i'd try a few of the cheap things before putting a ton of labor into the car.... i dont know about your mechanic but with me... 20 hours of labor would cost you about $1600