skunk2 IM only makes power from 7000-10000 RPM and your LS cant even rev that high. so theres your first answer. and #2 unless you are cramming a shit ton of air up in that manifold of yours then your stock IM will flow perfectly fine.
but if you really wanna make its fast then pick up a bottle of NAAAWWWZZZZ and a nice body kit for aerodynamics and then get a big wing for downforce. but make sure its above roof level or else it wont help any. after that i would suggest getting some octane booster from walmart so your car doesnt detonate with the spray because youre then gonna wanna supercharge the car and get a lightweight driveshaft (preferably carbon fiber). 18 inch wheels will also help through the turns after making all that power.
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