First, I want to say thank you for all the advise. Because of help from people like you, I have tackled projects I would never have and always succeeded !!!!!
I just bought a single sided, taped chaser, the kind you use a 3/8" rachet on and will be pulling the head to do all the work. I will also replace the valve seals and reseat the valves.
My plan is to first try chasing it, if that does not work, I'll tap it and lastly put in a time cert. I will chase and tap from the inside. To me it's not worth destroying a head for a days work.