Latley my 85 720 has been pinging more than normal, mostly when climbing hills or if its warm out. When I first bought the truck it had 65K miles on it and ran fine with our 87 octane cat piss. I've had it now for almost 4 years and it has 126K on the odo. For the last year and half, I've started to run 89 octane in it which helps the pinging but the engine still pings when I'm climbing or if its hot out. I bought the truck in Norcal and had it up there for three years. I have moved back down to Socal and I'm thinking the warmer average temp has something to do with it. On the flat, the engine runs great but when I start climbing and the engine gets warmer, it starts to ping and I loosed power. I am using the reccomended NGK plugs and there is plently of coolant in the system. I haven't adjusted the valves in a while so that may be the culprit as well. Would using hotter plugs help? Any thought/reccomendations would be helpful!