I was wondering if you could use the LQ4 / LQ9 / LS2 / LS3 Accessory Routing in a 4th Gen FBody, if not why not? Does the Alternator not clear the hood or something?

 

You cannot define an accessory type just by the engine it's bolted to, rather you should go by the chassis. The LQ4 and LQ9 are truck only engines, and use the truck accessory drive which will require you to run a truck intake. The LS2 and LS3 are typically Corvette drives. They're near impossible to make them work in a F-body chassis. That and they require a different balancer too.

Just get the F-body accessory drive