Have a 1969 Ford F-250 truck with a 390ci 4 bbl crab, point dist,auto trans and no smog compontents. When driving at about 60-65 mph up a slight grade the engine will ping. I am using 91 gas and set the timing down to 4 degrees btdc , pinging is a little less but still notocebly. If I drive the same grade at 40-45 mph there is no noticeably pinging. Love the truck hate the ping. Thanks Joe.
Posted on Jul 19, 2009, 3:20 PM from IP address 69.235.81.133