Header tune?
You don't have to get a tune, but I did gain quite a bit over the stock tune. Stock was 321/331. Headers, ORY, and Hooker catback and it went to 336/349. After the tune it jumped to 354/373. I think it depends on how long it's gonna be before any other mods like heads/cam, etc. If you don't plan on that stuff for a while or not at all then go ahead and get it tuned. If you don't it won't hurt anything, you just won't see the full potential.
Power jumped from 341 when I started my tune after installing the LT's and ORY to 356 when done. Oddly enough, my motor actually wanted less timing than stock to make it's best numbers with a 12.9-13.1 AFR.
