I remember here somebody tried to transplant a SV650 gear or some similar model, and failed. Don't you think Suzuki or somebody, would have made something with the right measurements? Why would the LS650 be so unique in its gear measurements. Of course, there are so many measurements that have to match, is there any hope? Needle in a haystack when the needle is a guess.  

Put a Dyna on it and cruise down the road basking in it's thumping glory!!!!

+ 1

You can still do the Kawasaki front pulley --- for more Cruse-ability .   The speedometer will be off about 10% , but that is easy to live with.  

Alright I admit it, I loved driving fast when I was younger. My first rides on a friend's then new Mach 3, riding my friend that owns a dealership's GS1100 in the early 80's when you lost the 85mpn speedo in second, and you keep going til the front wheel comes up again hitting 5th. You know your doing 140 or so and the damm front wheel still lifts when you shift hard. WOW fast bikes are great when you are young and immortal!
Now I have about 450,000 miles on 2 wheels. I have left the fast riding to the younger guys. I love the sound of my thumper cruising down the road. I have geared it up with both Kaw pulleys and a 150/90-15 rear tire, I have a solo seat and box/backrest and windshield. I don't go scratching around every corner.(do they even use that term anymore?) Actually crusing the flat, straight roads in S. Fla on my bike is like going down the road on a Lazy-Boy with a windshield. BUT I LOVE IT!!!!
The sound of that single thumping thru the Dyna is music to my ears. I know Dave's bike looks great and handles even better. I have seen bobbers on this site that look wild (for 10 mile hops). But to go to Columbia SC next weekend for a derby tournament, doing about 1300 miles in 5 days, mostly the first and last, I NEED to take stuff with me. I'm not going back to a Gold Wing where if you're packing lite you only take the 2 slice toaster. But I think I should be able to take the min. for a week's trip. Yes I know even with a good rainsuit you get wet when it rains. Did 40 miles thru a downpour last Sat. But compared to riding in a box, going down the road on a bike is almost like flying! You don't have to turn in a corner, you just think and lean and the bike and you are one.
Riding a motorcycle, when done with common sense, can be a soul filling experience. When done carelessly, it can be terrifying, painful, and extremely unforgiving!
I won't seriously pick on anyone who rides, on a scooter, Gold Wing, chopper, dirt bike, or even a sportbike. (I will however complain when they pass me inches away at 100 mph faster than I am going!)
The point is to get out and RIDE!!
If you have and like a S40 or Savage and want to mod it to your personal taste, style, and budget, GO FOR IT!!! The basic bike can be like raw clay to a sculptor. The changes and mods you can do are endless. But don't lose sight that it is a motorcycle, not just a tool or a work of art,,,,,,RIDE IT!!!