madmax, i think youve got hungup on these lifters somewhere along the line and cant see the forest for the trees, these people are telling you the correct way to adj. the valves and if you do this correctly i dont know how they could build up to the point the valve wont close, but run fine for 300 miles. if you adj. your valves and the motor runs for 300 without any problem and then start to run bad id be looking somewhere alse other than valves for the problem like maybe a fuel problem. get the motor running good again and then check the comp. on a cylinder thats easy to get to and when the motor starts to run bad the next time check the comp. again on the same cylinder and if it stays the same the lifters are ok, then you can check something else. let me know about the comp. thanks, mike