I am in the process of doing the same thing.  I called my local Bando distributor (co. who makes the stock belt) and asked about a longer one.  He quoted me $135 for a 150 tooth belt which would give about 4.5" stretch by my calculations.  The only thing that I am unsure about is the rating of the belt.  The one he quoted me on is an "HT" grade belt.  The downside is that it is a custom order, and I can't return it after we've ordered it.  I am still waiting on some parts for my Savage before I go for the stretch.  I want to take a stock savage belt in to let him see if he thinks it would be a good application.  As with all things chopper related, there is an element of risk when building something custom...  If you find anything out, let me know.  If I get mine done first, I'll post something here as there are several people interested in Savage choppers.  --Jay  

You could allways try a chain.

Clive W

Clive is right about the chain.  There are rice burners and Harleys with belts, but I'd go chain so that I could play with ratios.  I understand that it is possible to get a front sprocket for a Savage...with a little research.

I like the belt under normal conditions, but here lately I've had to ride in the wet quite often to work, and the silly thing squeaks too much when wet.  If I had a chain drive rear wheel, I'd change it.