I have a 72 pontiac 400 that pings and knocks upon acceleration. There is no timing tab for me to correctly time it, however I have hooked a timing light up to it and turned the HEI distributor so that the mark on the balancer is pointed in the general direction of where a timing tab should be. Also, I am getting a steady vacuum reading of "17". Should I install a timing tab, if so what degrees should it be set at? Should I try premium gas?
have the same problem?
Wednesday, January 5th, 2011 AT 8:18 PM