Lifter tick after shut down.

Ok... this is the dealio

I have a lifter tick like the lifters are bleeding down after the engine is shut down just like in this video.

[ame="https://www.youtube.com/watch?v=eFFLCDWpauk"]https://www.youtube.com/watch?v=eFFLCDWpauk[/ame]

My engine is a SB with hughes engine 3038AL 110deg. 515/535 cam and their lifters.
Good oil pressure on start and throughout the rpm range. I am running a 20w/50 oil.

Rockers are MP heavy duty, stamped rockers with MP pushrods.

Are the lifters failing?