The GT500 chin spoiler is designed to fit the GT500 bumper. If you put it on your V6 bumper, no it will not fit. But if you upgraded to a GT500 bumper, then yes it will fit. Not sure if the GT500 bumper is a direct fit though.
Procharged D1 on 12Lbs, MPT 93 Tune, 73mm BBK TB, Ported Upper/Lower Intakes, BBK Shorty Headers, FRPP Cut n Clamp Xpipe, Borla S-Types, Barton Short Shifter/Blowfish Bracket, SS Clutch Line, Whiteline Trans Bushing, One Piece Driveshaft, Front and Rear Tower Brace, Whiteline Front and Rear Sway Bars, Whiteline Adj LCAs/Adj UCA, BMR Relocation Brackets, BMR adj Panhard Bar, Eibach Sportlines, FRPP Dampers, 20" AMRs, 3.55 gears, Brembos