Ive decided not to turbo my LS and save the money for another project. I plan on leaving the engine alone but i have got an air intake new headers, and a custom exhaust. So my question is will i need to chip the ecu to take full advantage of these mods, or will a shop be able to tune the stock ecu?

no tune needed there is nothing to tune

Actually to take full advantage you need tune. My tuner does street tunes for like 150$. When you tune you add timing and you can correct the air/fuel mixture which was thrown off by the I/H/E

save your money for pistons and cams something that will throw your timing off then u have a reason to tune i have never had my timing throw off or needed a tune from i/h/e you will be wasting your money and won't notice a difference but that is just my 2 cents

yeh its not really needed with that kind of add ons

to be honest with you all, when you add i/h/e you feel a bit of difference. then when you tune it, its like a whole different car. if you arent gonna go any further with the car take it in and get it tuned. you will be very pleased at the results.