I wanted to add these photos for information of some of the lifter failures. 1492 is a factory hyd. lifter 6506 and 6500 is a bottom photo of a failed replacement lifter , the last photo is the rocker arm ball end.
What I found was the rocker ball end did not fit into the the seat at lifter and only caught the edge which damaged the rocker arm. This also caused the lifter to not spin or rotate (this will wear down a cam lobe). You can also note pitting on the lifter base but that lifter also tried to spin but with rocker hanging up in the cup edge it damaged the rockers and results was worn cam, lifters and all rocker arms.
This damage was found on 3 different engines here in GA and built by other people and most only had less that 500 to 1000 miles on engine.
I took one of these engine apart and took photos so we will have this info. here and it may help someone.
Some of the hyd. lifters out there are giving problems and it's getting harder to find hyd. lifters so you can get your factory lifters rebuilt and base resurfaced at this time and should work for you.