Wow you are in for some fun!! It will all be worth it when it comes together!
What kind of cover do you have on your xfire engine now? I accidentally purchased an 8 cyl airbox and nose piece for my xfire, of course the airbox fits ok but the nose piece doesn't. Might you be able to use my airbox and nose piece for your new engine? If you are currently using a MB airbox on your xfire I would be willing to trade.