Just a few reasons that excessive guide clearance happens------wrong valves, wrong guides, incorrect rocker/pushrod geometry---- mix up of standard and metric specs---example would be use of metric valve stem and standard size guides-or wrong size reamer or hone for finishing the guide---wrong valve length to accominate springs/retainers causing issue with rocker geometry/pushrod lengths---
show us some of the seals and also port area near wear push rod is-------
angle of engine mount can cause poor drain back of
oil in some cases ----
high volume
oil pumps and lack of control of
oil supply to rocker shafts can cause high oil level in valve covers-----
Also in that video it looks like those guides are too short-barely above head mass------
I'll see if I have time to photo graph some of the equipment needed to measure valve guide clearances--- also the diamond guide reamers for the guides--------