Ian,
I'm sorry there is so little modern Alfa info available here. There aren't many of us who have even seen any of Alfa's post-1995 products, as most of us are in North America, mostly in the U.S. I think your engine is different (and the t-belt layout improved) from the U.S. distribution 24V of the mid-'90s. Good luck. Do you have a manual for your car?