will a 427 lingenfelter engine fit into a 4th gen camaro without have to cut the piss out of the firewall or anything

Depends on what engine that 427 was based on. Why don't you give them a call, they do those transplants all the time.

the 427 they use is a LSx engine. if your car has a LS1 it is a bolt in (as long as your trans. and exhaust are up to the task)

Lots of $$$$$$$$$$$!!!!!