gears would be first and foremost for me. next up would be the bolt-on stuff, headers, exhaust, intake. then maybe upgrade ignition system and nitrous!
first things first, make sure the maintenence is all good
my first stop would be to just do good regular up keep and replace plugs/wires/distributor etc.
I would also decide what I wanted out of the car (realistically) and then determine the steps to get there rather than realizing half way through you either wanted more or cant afford what you wanted.. or it will take 10 years etc etc
__________________ 2003 Cobra Vert (Redfire) #3938 of 5082 @ 05/27/2003
472rwhp/493rwtq -Modification List - Dyno Sheet 2012 Mustang 3.7L M6 (Kona Blue) 2011 Ford Edge Sport (Red Metallic)
I remember hearing something guys do with the 5.0's involving the timing, bumping it up to 14 degrees or something? I guess it was a quick "free" mod for the 5.0's. You'd probably get some engine knock or pinging though running 87 octane.
12 Black GT500 SVT PP l VMP TVS l JLT123 l O/R X l 28x11.50Rx15 M/T Street R's l BMR Suspension l Recaros
03 Sonic Blue 3.8 / 17 Magnetic Fusion Sport 2.7 EB
It all depends on what your goals are for the car. Research and have a plan. Otherwise, you may wind up buying parts only to replace them again further on down the road because they weren't what you needed to achieve you goal.