I have a 1996 fxd with the 1340cc big twin evo with thunderheader exhaust and I got a nasty noise coming from my engine. I was doing 60-70 and let off the throttle and it ran away on me so I killed the engine and pulled over. Put it in neutral and fired it back up and it was good, no noise. Then it wanted to die a little but ran ok. I got to where I was going and shut it off then the next day it started fine but I went to take off and it felt like it stalled it. After that it took jumping the battery to get it started again and a nasty knock started immediately will in neutral. I replaced the rods, lifters and gaskets. One of the rods was a little bent. I started it back up and the same noise. The valves look fine, no real metal in the oil. I just recently replaced the air filter before that. The bike also spends a lot of time between 60-80mph. Any ideas?