they can be adjusted but apparently its a nightmare job only qualified machinists should do you'll have to remove the plenum, valve covers, cams, cam gears, timing belt, etc. youll need the sst and a whole host of other tools, most mechanics dont even want to do these jobs on the 3vze, not trying to talk you out of it. just heard it was a serious PITA...
Cheers
Their is no rocker arms on a 3.0. The ticking is excessive lash you hear in the valve train and it is quite expensive to adjust. I say live with it if it is not too bad. I have had two 3.0's and both of them had a tick and I put thousands of miles on them without any issues.
Yes keep an eye on your oil.They are a pain to adjust they use shims instead of a nut and screw.I adjusted mine last time I did the head gaskets and don't want to do another.I sold mine and bought a first gen with a 22re
There is also a very distinctive and quite loud clicking noise from the injectors on these older engines. I know the 22RE is famous for that.
My engine clicks like hell, and I had a friend/professional mechanic adjust them for me twice when we did my front end rebuild. Still clicks, so I ignore it.