A cold air intake will round the headers and tune out nicely. If you wanna increase the acceleration then you could do a torque converter and a gear swap. The torque converter will come in handy for later when you do a cam. As far as a cam, I've seen them priced as low as $1300 for a swap including tuning. Some places are more like $1800. But yea a cam, headers, tq converter, and gears are gonna be your heavy hitters as far as performance goes without getting into forced induction for several thousand dollars. And there is always nitrous...
2017 Camaro ZL-1 A10
2013 Jeep Grand Cherokee Hemi 5.7 - Tuned!!
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