Re: 0 compression
Just a head gasket might make you happy but it doesn't make a difference , because once you pull the head you need to replace the gasket anyhow, along with anything else causing the problem.
There are no valves involved in the combustion cycle of your motor.
Once you remove the head you need to verify that the cylinder walls are not scored, pistons are not cracked, broken, chipped, etc. You also need to verify that the head is not warped in any way..........and......
In the future when you are posting a question, include details, for many of us, we will only put the same amount of effort into our answers as people put into their questions......I was feeling generous tonight and kinda bored otherwise your answer would have resembled this "well then fix it".