I would try to find a 450r carb, but other than that it looks good. Who are you having build your motor? I see you live in Missouri and I know a guy in KC that does great work.
416 - JE 12:1 piston, port and polished head, stage 2 hotcam, Curtis Sparks X6 exhaust, Lonestar +3 LT A-arms, PEP LT shocks up front, Stock in the rear, Laeger swing arm, G-Force +4 axle, Pro Armor nerfs with fat pegs, White maier plastic, Laeger steering stem, Pro Taper handle bars, ITP Baja rims with Holeshot MXR6 tires, Blingstar V2 front bumper, Denton steering stabilizer