Best way to troubleshoot a miss ??

[7.3n/anut]

Always start win h cheapest fix. Diagnose for days on end and look for variables if need be.. better to have a lot of time and little money haha. All of those tests are a cylinnder test. Ill take a while

 

[Agnem]

I'd do a compression test. Not trying to scare you, but it could be valve related. Saw that once. The valves wouldn't seat at a specific RPM.