i have a 250 with 7.3 turbo went out to start it after a couple hours of sitting. Then started to hear banging. one of the cylinders was about 30 degrees colder than others. Oh by the way i live in alaska gets kinda chilly
Well now, there's your problem! Ether will bend push rods. You're lucky there wasn't an explosion...well maybe there was, but it happened in the cylinder instead of intake.
That doesn't make sense to me. Maybe on startup but there are plenty of people on here that take a little nip of ether once in a while. Plus, the OP said he was ddiving 65 when it happened. Something in the lifter or valve seat had to let go. The machine shop might shed good light.