Noise from engine

If it is a lifter, you can try and disassemble it and clean it out. There could be trash in it. I have heard of people swapping out a bad lifter with a new one. What are your other options really? Change it all, new cam and lifters? 16 more chances for another bad lifter? Buy the absolute BEST set out there for hydr lifters and swap them all? One bad lifter puts you in a pickle. There is always risk with hydr lifters. If you go the one lifter swap, make sure it spins as you turn it over. Lube the contact area.