Following is a list of available mods for your car:

Carbon fiber air cleaner +10bhp/+8 lbs.-ft $950.00
5.0l engine conversion +72 bhp/+78 lbs.-ft $12,950.00 (does not include installation)
6.0l engine conversion +113bhp/+103 lbs.-ft $27,450.00 (does not include installation)
6.0l engine conversion with high perf. cams +134bhp/+115 lbs.-ft $32,750.00 (does not include installation)

Also available are performance final drives, limited slip diffs, transmission upgrades, suspension and brake kits, and sport mufflers. If you need any more information let me know via the forum.