if you want it to be really reliable sent the heads out to RK Tec to have them reshaped for the combo,then you shouldn't ever have to worry about detonation, and it would be an even stronger set up.the reshape should be around $150,and its worth it.and yes it is a strong set up!
Can you email me some info on what you mean detonation. A buddy of mine has a 99 500 ZR EFI that has a D&D pipe and chip on it. Since it was installed this thing has run like $hit. The dealer has rebuilt the clutches, new stator, and god knows what else but no help. It backfires when you start it, then when running it either boogs at around 6500 real bad or if you jump it over anything it dies then refires. We have tried bypassing the kill/throttle switch, and are about to give up on it and trade it, so any help would be appreciated. E-mail [email protected]