Thank you for reading. This is my first post. I have a sand bullet turbo hayabusa sand rail. Gen 1, no gauge cluster (for codes). Power commander for fuel and spark. It started huffing black a bit from the tail pipe before the last dune trip. Then a piston lifted a ring land and scrambled the valves. I've replaced a rod, base gasket, pistons, turbo gapped rings, cylinder block, head gasket, head, cams, and shimmed the valves. Leak down only 3 percent in worst cylinder. Cams not a tooth off verified many times. When cranking with coil packs off but plugs in, no problem. As soon as coil packs are installed, it gets very angry. Clanging during cranking can be heard and felt in frame. It will start and idle with some throttle input to start. Then it sounds like it's running on 2. It then starts rolling coal like a diesel truck. I then swapped the cam position sensor. Then swapped the stator/crank position sensor. Adjusted the throttle position sensor. Then deleted the dynojet boxes to bare stock ECU. Nothing helped. Seems like the blown top end was a symptom of the real unknown problem. I don't know what to do next. It ran great for years with the same exact setup. I've read many other posts but I'm coming up short. Please help!