My '01 had 54000 miles when the valves were checked, 5 were out of spec to the tight side, 4 of the 5 were exhaust valves. I replaced the carb boots at the same time, they looked bad but none were cracked all the way through. The inner metal sleeve does not run the entire length, there is a 3/4" area in the center that's rubber only, I'd guess to isolate vibration.
A valve adjustment is typically out of the scope of a Maintenance day project at Don's unless you can get some members to commit to helping, it's at least an all day job, could be longer.
You need to find someone to fix your mechanic, because his advice is out of adjustment !