Running on a DOHC with Power steering removed I used this belt.:-
http://www.camskill.co.uk/products.php?mode=search
hope this link works if not go to camskill website and search for 6PK1285
I think the part number system is fairly self explanitory in that 1285 is the mm dimension
In hindsight I should removed the belt tensioner as well as it's not really doing anything for me with the belt setup as it is but hey ho I'll find another belt when I get 5 mins
Rapidtornado