I personally would advise you to keep the serp belt. Look for an ABA or VR6 water pump pulley - it is driven off the serpentine belt rather than the V-belt. Since a picture is worth 1,000 words:Pulley: 028 121 031EBelt: Gates K060408HDIt's SO easy to deal with a single serpentine belt with no v-belt. All you need is a big crescent wrench on the tensioner arm and bingo, belt removed or installed in all of a minute.If you do go this route it is HIGHLY recommended that you upgrade your alternator pulley to the 'clutched' version they used on all the TDIs. The AAZ was the first VW diesel with a serpentine belt - there were some issues relating to the crank nose caused by the mass of the alternator. Search 'AAZ crank nose' on here and you'll find lots of threads about it. The AHU alternator pulley fixes most of the cause of the problem.