I'm running a v-belt with no issues. You don't need to tighten it too much or you'll wipe out the alternator/water pump bearings sooner than later. Make sure all the pulleys are aligned perfectly. I used a straight 1/4" or 5/16" dowel (Home Depot) about 12" long. Seat it into the "V" of each pulley and rotate to the adjacent pulley - it should line up with all three.
I also machined the crank for the "D" sprocket from the TDI engine and used a new bolt torqued to spec.
I have no experience with the serpentine setup (assuming you mean one-way clutch) on these engines, but I have used one-way clutches on high cycle machinery and they can fail. Personally, I like to keep things simple whenever possible.
I would use the v-belt setup if you have all the pulleys and brackets. The serpentine setup is a good choice IF you do not have a matched set of pulleys.
When I purchased my 1987 golf diesel it had 3 different pulleys from 3 different setups. The crank was a non-ac pulley, the waterpump was an AC pulley and the alternator was from a 8v gas vw. After having no luck tracking down a complete set of pulleys anywhere I opted for a Serp setup that I purchased on this forum.
Thanks again guys.
My rod bolts arrived yesterday! I'm a little nervous about the torque specification I haven't been able to find a good manual for this engine. (I bought a Jetta Bentley, which has very little AAZ info)
I've seen 22 ft/lb and 1/4 turn cited, but I don't know if this is for both types of bolts. My engine has the earlier bolts. (028 105 425G)
And I do oil the bolts, right?