BEST MOD UNDER $400:
3.73 or 4.10 w/Tlock $400 (installed) end of story, if you drive on the highway you will like these gears better depending on the tranny you are running...
3.73-Stick
4.10-Auto
BEST MOD UNDER $250:
JLT CAI $230 painted and delivered! Really any CAI will help, but I like the fact that it can match the color of my car! Which brand CAI has been beat to death, so just pick one you like. JLT or the Densecharger are my two favorites
BEST MOD UNDER $200
Short Throw shifter of almost any brand, which brand is better has been beat to death in many previous threads
BEST MOD UNDER $150:
Aluminum Underdrive pulleys