is there a difference between the left and right head on a 5.3l. I no that there is a sensor on the front part of the driver head. but there is an empty hole in the rear of the passenger head also. I ask because there is a broken bolt in the front of the passenger head where accessories would mount to and I need to use the hole to mount an ac unit. I figured I could just swap the heads around and have the hole again. didn't see a left and right marked on the heads.

 

Yes, you can swap them, it is not a problem. Just swap the coolant plugs around. Have you tried drilling and extracting the bolt,, ITs alot easier than swapping heads around. If you can drill it get a good extractor, and then start the engine up and let it get to temp. kill the engine knock the extractor in, and give it a shot. The engine heat will help loosen it up. If it comes out, all is well, and if you fail, hey you lost nothing because you were gonna swap the heads anyway.

 

Agreed ^ center punch the bolt very carefully. Drill it and use an extractor set. Never failed me yet. And if it did you can just drill it out and helicoil it. A lot of people are skeptical but if you do it correct it is actually stronger than before.