My 1985 2.8L Camaro's engine would probly win the worst noise ever herd from an engin award. It has a bad banging sound at idle speeds and gets louder as the engine speeds increase (2000 RPM's you can't here your self think). I think its a bad wrist pin or piston rod.
also the cam has oiling problem's and they like to break! then they crack the block!
get a 3.4 cam for the 3.4 upgrade motor for the S-10's that GMPP offer's and rebuild the bottom end and head's...or better yet get a 3.4 GMPP motor if you want to keep the 6 banger, they work great!