For the most part on Pontiacs "Headers Suck!!". You may need to lift it off the mount , make sure to remove trans cross member bolts. i just put on the Ram Air Resto 2.5" aluminums and i love them, when i took my Three pipe jet coated headers out i counted 5 spots where they were either rubbing or hammering a dimple into them, from frame, bolts and who knows what else. The first set of 4 pipes i put on literally took 5 hours, 6 busted knuckles, and half my budget into the "Swear Jar". the 3 pipes were better , until i saw what was going on with them under torque.
No wonder i could never get that lifter "tick" out, it was the headers. The RA manifolds will fit in without moving the engine with a little maneuvering and are SOOOOOOOO! much easier to get bolted in with the right torque. also they have down pipes so they hug the floor pan and you will never hit your header mounts or pipes on a speed bump . All clearances are at least a fingers width and gaskets are Heavy duty.