03 5.3L; Upgraded lifters?

[sully]

I've got a lifter that is knocking at start up, it stops after a few seconds but my mechanic said it is loosing it's prime (whatever that means).

I'm guessing that it has hydraulic lifters and am wondering if I could convert it to rollers or do anything else while I have it apart to upgrade the valve train. Any suggestions would be great!

 

[03_Denali]

You already have hydraulic roller lifters. My guess is that you have cold start knock CSK, which is normal.