I just bought an 03 Z71 AV about 6 months ago. So far I have a cat back dual exhaust with a magnaflow muffler, flow tech ceramic headers, new aftermarket wires with "upgraded" coil packs, and a cold air intake. My question is, is a tune worth it, or am I good with what I have. The shop I went to said I should so that the parts will work better together, but I would only be able to run 93 octane after the tune.I'm honestly looking for better gas mileage hence why I also did an electric fan conversion. Any thoughts at all would put me at ease from the dreaded biting my nails worrying about what I should do.