To answer your question KC135_flyer, you do have to grind out your frame a little--not much though. If Jon says he could do it for you before he chromes it, then I would go with that.
I have the 240 kit on my bike. Purchased it from Jon. I've got an 8 inch over arm on it and it rides like a dream. You don't loose that much in the twisties that you can't make up for in the long run. You lose a little in the quarter but not much. Once you put a shot of NOS on it, you'll be better off than most think.
Let me know if you have any other questions. Oh by the way, buy the ZZZ O-ring chain (gold) if you get the kit. It is the no stretch one. Anything else will stretch and cause your wheels damage.