Grounding to the head is no problem, especially if you're also grounding to the starter or to the block next to the starter. What are you using for coolant? Distilled water might help if you are using tap water. Some sort of additive is also a good idea such as water wetter or something like that.
i have read in a few places not to use distilled water. I'm not a chemist but it was said that distilled water has been stripped of all minerals and when you put it in you motor it will eat the metals to try and balance itself back out. it said use softened water whatever that is.
