Got a LLY c4500 dump in that needs CP3, possible injectors, and head gaskets. I have no experience working the the big chassis' trucks. Is it possible to do this job without lifting cab or pulling engine? I would lean toward pulling engine before cab but maybe it's no big deal? This truck's dog house cover wont come out either without pulling the passenger seat and loosening the pto control box thats bolted to floor in the center!