I have an 05 Silverado 1500 with the 5.3L and 83k miles on engine and trans. I have exhaust manifold bolts broke off in the head so so it ticks a lot from the exhaust leak. I am also getting a code for the knock sensors and my truck just started misfiring and seems to have a major power loss. Im planning on getting new heads and headers, a cam, and knock sensors. I'm trying to figure out what aftermarket heads, headers, and cam I should go with for a little added hp. And if there is anything else I should replace while it's apart that far. I want to get a little more hp out of it with out spending too much.

 

Don't waste the money to replace the manifold or pay someone to drill them out. I recommend getting a KAP exhaust manifold repair kit. I have used them on my own vehicles and some of my customers and it goes so much more smoothly. Plus, you don't have to worry about the new bolts just snapping again in a couple of years. My brackets have been on for 7 years and haven't had any issues. Just make sure you get the authentic ones that are made in Minnesota because there are some copy cat ones floating around out there. The real ones have a part number stamp on the bracket itself. Works for me, so just another option I'd throw out there.