My vette only has a CAI, so pretty well stock. That said, I'm still going go over the VE and MAF to make sure they're as good as they can be. Lowering fan temps and killing that stupid skip shift alone was worth the $125. So far I don't even have a wideband installed because I'm planning to get some longtubes in the next couple months, so I figured I'd waste my last bung on that. As of now, the only thing that I've done to the tune in an attempt to increase performance was to lean out PE a bit, hoping the stock engine with stock VE tables is accurate enough to make a positive difference. The real reason I'm posting this is because I've seen a lot of dynos where simply bolting on the headers only nets ~10whp, but a tune pulls out another ~15whp. The fuel I can handle, I know what I'm shooting for there, but the timing isn't as intuitive. From my research, it seems in stock form they're quite fond of their 22* WOT and increasing it further wouldn't really do anything for power (sea level thinking here, I get more at 6200'). I have a difficult time believing that correcting the fueling for the headers alone is worth 15whp, so is anyone willing to divulge how much the engines desires change for spark with headers?