So I've been working on my 99 K2500 for a few months off and on, mainly off since winter hit and I can only work outside. I had been tracking down a miss, pulled the injectors and tested them, all of which seem to be working and firing fine. Before all of this happened the starter had been grinding and it turns out that the previous owner messed up one of the starter bolt holes and only one bolt was holding the starter in. It will need to be drilled and tapped and I plan on putting in a helicoil to fix it. I know it's critical to get the hole drilled as straight as possible and I don't really trust my ability to drill the hole upside down so I plan on pulling the engine since I'm guessing the flexplate will need to be replaced too. I also want to pull the engine to replace the oil pan gasket, oil pump, and clean out the engine bay and engine. Any tips on doing this since I've never pulled an engine before? I'm guessing it's best to unbolt the exhaust from the end of the header rather than taking off all 16 bolts from the head?