I'd assume you also dug up the other VV related threads on this forum. In a couple of them people discuss running into clearance issues at the point when they first try and put a chain on it and put the rear end together. I recently got through that point of the project so I figured I'd share my experience. I am sure that to anyone that's done a few of these this is commonly understood,
   The first issue people used to mention involves chain clearance over a bottom cross support piece that some choose to weld in place. When mine was shipped that piece was really just a spacer to keep the thing together right in shipping. My chain runs clear and smooth. I will probably run a small chain tensioner that mounts to the side rail instead of the big spring loaded one that most seem to run with the big bump to clear the cross piece.
   The side to side clearances are another story. First off just cause your frame rails are a perfect 8.5" up higher in the loop, the measurement you need to pay attention to is at the bottom. They tend to creep in a bit as they run their length.  The little blue print that David Roy(great guy) sends with the tail is accurate. The key is getting your wheel spacers right. The side to side clearance between the frame rail and chain is pretty tight. The spacers are the critical component to getting everything to go together. Just make sure you are making measurements from the bottom of the rails or the axle plates and not the top when you're trying to center everything else. The inner frame rails should be 8.5" at the bottom also.
   Keep in mind that the axle plates aren't specifically made for our bike. They are designed to accommodate a 3/4" Harley axle. You will need a bushing to accommodate your 17mm stock axle  (get one from VV. They're cheap and easy). Also you won't be able to use close to all of the length of the slot for the chain adjuster cause the nuts that hold down the sprocket will hit it. I've seen at least a couple of others get longer chain adjusters only to realize that it's the nuts that limit travel. There's sufficient travel as is to tighten the chain.
   

Any more progress on this?  I'm working on a VV roller and just bought a GS550 wheel off of eBay and the VV axle bushings.  Appreciate the info so far!

Thanks!  Always looking for threads from those that have gone before  

I'm in sort of a weird position.  I bought one complete bike (a '96), but he threw in the VV kit, an already cut frame that included the title, and a complete front end.

So I'm doing a stripped down bobber-ish job on the complete bike, but also working on the VV half-bike as well.  That'll probably be a long time coming, since I have to buy an engine, chain conversion, and all the other bits and pieces to make it into a complete bike.  The GS wheel will at least get into "roller" status

Anyway, looking forward to seeing your progress.  It's looking awesome!

I went with a chain tensioner that I got from TroyFab in Rhode Island. It is a nicely made piece. I was pleasantly surprised when it arrived and I pulled it out of the package to find that it is nice and heavy and well made. It also mounts to the side rail which is nice on VV tails.  The tensioner isn't necessary for chain clearance issues within the frame as it was on a couple of the other VV related threads on this forum.  The chain runs clearly through the frame without it but is a long chain and I'm running a pretty full fender hence the tensioner.

The clearances between the chain and frame rails are tight so I figured the tensioner was a good idea to help keep everything running in the right places. Im not worried about the chain slapping it but I'm running a full length fender and there is only so far you can go in the axle slots. This will allow me to tighten the tension on the chain as it stretches without worrying about running out of room under the fender.