I suggest looking at it like this:

The 2.8's are not known for lifter noise. If you have lifter noise, something is wrong. That wrongness could just be a sticky lifter, but it could be a few more things; expensive things. Worn or misadjusted valves, worn or cracked rockers, or even a flatened lobe on the cam could all do what you are describing.

While we treat the tick-tick-ticking from the 3.2's as a factory installed option, I would suggest you consider tearing into it to find out what is the problem and fix it. If it is someting that is on the more severe end of the scale, you might even catch it before it frags and takes out more parts and pieces.

An oil change is probably the easiest place to start, but adding chemicals (especially to an older motor) in hopes of making the problem go away could be asking for problems. The chemicals are solvents. Solvents think your oil. If this is a bigger problem, restricting oil flow and lubrication might not be the best thing to do.

Good Luck,
Michael