Ambitious to say the least, especially considering what Stephen mentions.
I see this is your first post. Welcome! This forum, and the v8 e-mail list before (v8sho.com) have seen many a new sho owner asking about somewhat implausible mods. Nothing wrong with asking, or of pursuing them even (this is the USA after all), as long as you have ample feedback and know what to expect. I can't speak to the technical/fitment aspect of what you propose, but in a nutshell:
You'd be taking a seasoned old Amish-made axe and ripping off the head, breaking the well-cured pitch resin bond, to replace with the latest Fiskar model - a new, lighter one that would require modification of the original shaft, the bond with which would never be as good as the original head . . .
I'd only hope that the new "axe head" (v6 EB) can be obtained without having to sacrifice the "shaft" (Gen4 body) from which it came.; and, I'd hope that you'd have a Gen 3 body that's in near excellent shape inside and out. If so, and assuming you could pull the swap off, you would gain instant VIP access at all future SHO conventions! Might even be able to turn a profit if Mr. Leno attends.
Now, about that fuel tank relocation . . .