The best site for Impala SS info 
http://www.impalassforum.com/
Impala SS Club of America
I'd recommend a good cold air intake, tri-y headers, catback exhaust, and PCM reprogramming for starters.
If you want to make it the most fun you've ever had......put a T56 in it.
Add some suspension upgrades and you will really fall in love with it.
Randy
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1995 Impala SS
T56 Six Speed, Wilwoods, Tri-y's,...
1964 Riviera
31k miles