My daughters 02 Diamante is getting valve clack from the rear bank. Pulled intake and replace the 6 exhaust valve lifters on that bank. No change, wondering if replacing the 6 intake lifters will fix it???? What do bad lifters feel like when compressing them?

 

it will be easy to spot shot tappets,
you should have actually taken all 12 out and compared, then decided which if any to replace.
personally, i put them back in the same arm and same place they came from, but apparently that isn't neccesary.

 

Mine, I replaced the lifters for both banks but there's no significant changes, in terms of clanking and oil splashing at least 10-20% less. I see significant wears on the shaft as well as in it's rocker arms. So, what do it expect. The best is to replaced those parts and probably made more positive changes.
Good luck..