I few weeks ago I did the 63" swap and just got around to testing the rear flex and clearance. I did some trimming but the tires are hitting the inside of the wheel wells. I currently don't run any bumpstops but I was wondering how others resolved the issue. I'm running h1s with 3.75" backspacing. With a spacer or less backspacing the tires will hit on the outside of the fenders. I would like to keep the wheel wells and the back seat for now. Somebody give me some options.
) I ended up hacking the entire rear floor out and now I'm trying to get another body and not do so much hacking to that one. I really miss having inner fenders. I'd try limiting up travel with some bump stops. You really should limit those springs anyways because I hear they get worn out pretty quickly if you arch them negatively. Maybe you could take out the BFH and relieve some aggrivation on them until the tires hit less or until your seat rubs on the wheel wells??? 
Without a bar of somekind, the springs wil be alot more prone to bending. I bent mine, but that was from a full throttle, 7 minute run through the tank trap.
