Re: 'Tappets' noise from 24 valve 3 Litre GTV
The V6 Alfa series didn't come with Cam Variators mate, only the Twin Spark models did.
The 3 Litre V6 lump in your GTV is more basic than the Twinnies and should hopefully be easier to fix. Fingers crossed anyway!
Also, I'm certain that the V6 later series engines had a different tappet set up meaning that they couldn't 'go', as in you wouldn't be able to hear a tappety like noise and have it be the tappets. I'm sure this is the situation with the 156 V6 anway.
Now it could be the Cambelt itself, as although unlikely, they can give warning as to their 'About to go' failure. If this is the case you are looking at around £600 or less for a full cambelt and tensioner replacement.
It's alot of money but at least that way you know it's been done properly and won't have to fork out mega bucks if it breaks, and with a shelf life of 3 Years/72K Miles you'll do okay once it's been done.
Then again, it may not be this. I would get it checked over by an Alfa specialist in your area if you can.
But in answer to your question; No, the V6 does not have variators of any kind.
Hope you get it sorted soon mate as they can be cracking cars when working properly.