Well i guess i learnt allot about detonation after blowing 6 headgaskets within 6 months from detonation problems, im glad i fixed that problem (lower comp, modded chambers etc). Ive also discovered that stockas can take heaps of pinging compared to similar engine making more power. We had a mitsy colt. Pinged like crazy especially the more it was loaded up and the hotter it was. It never broke down in the 3 months it was around. My turbo 1200 when it had the problems, faint pinging only above 5k rpm only heard it ping on approx 10 diff accasions and backed off straight away, a total of no more than 10-15 seconds and a head gasket would fall out the side of the block! Frustrating. My word of advice would be that if even the faintest of pinging is heard, pull over and back out some timing. Also have a safety margin there, and a large safety margin at the expense of power if you intend to flog it through hills let it get real hot, let tyres boil with little airflow etc. Ive also found octane boosters have done nil for me, interestingly enough once i was forced to fill with 95 instead of 98 and that required a lot of timing retard...