will thinner headgaskets cause valves to start ticking? I believe i have .030 cometic gaskets and i have looked over everything and even put in new lifters and after it gets hot it ticks at higher RPMS. idle it is fine. it is a 2002 with a stock 1200 conversion. this is driving me nuts. I got the kit from craigslist and the packages were opened but im not sure. I got the metal head and base gaskets with a complete topend from a 2002 stock 1200. when i first did the conversion it didnt start ticking for atleast close to 100 miles. then i changed the lifters this friday and about 100 miles it started again but not as bad as the new lifters.