I'm building a (very) hot cb350. Most of the things I've seen, aren't terribly needed, though things may be different for the cb450.
Making sure the oil pump works well, and everything's getting oil, and an oil cooler, are all I can think of that I need for the 12.5k redline I'll be pushing on the cb350.
Those needle bearing covers are cool and all, but not neccesary. Only thing I see I need there is the steel cam roller.
That's not to say that tons of things aren't needed to make it fast, and I don't know the limitations of the cb450 (haven't had one apart yet, but from all I've read, it's a bit of a #$%* to make fast), and maybe the oiling and cooling system leaves a bit to be desired on the cb450?
Dunno. Hope I'm not building a grenade 350. (50rwhp, I hope..)