Chuck will retune if youre unhappy with the outcome first time around. Similar to what i think blackbear does with online tunes (at least what I gathered from reading posts, have no personal experience with a blackbear tune).
As for future mods I think there's an additional cost to retune.
I got an AFE stage 2 intake prior to tuning so he dialed in everything pretty good. If I were to get headers later on I'd probably pay and get a retune from him.
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