I tested compression last night on a cold engine (155 psi top and 140 psi front cylinders). Will compression increase or decrease with a warm engine? Is the difference in pressures significant? What is recommended minimum pressure?

Also, the top cylinder spark plug wiggles more than it should. Back it out 1/4 turn and the tip moves almost 1/8". The front cylinder wigles a tight 1/16" and is more what i am used to. This plug was also loose. I assume it vibrated loose? Did vibration cause the excess wear? Is there something that can be done to fill the void like plumbers pipe dope or teflon tape?

Thanks again.