Where in MN are you? Where'd you buy the car? Dealer or private party?
1992-1995 SC'ed 3800 require 91+. 1996-newer say 87, but that is if you absolutely never step on it.
For mods you should start out with plugs, 180* t-stat (helps big time to keep heat soak to a minimum in the upper end), remove the MAF screen from the throttle body, remove resonator from exhaust (just behind catalytic convertor), free flow muffler, Tranny cooler, spark plug wires, etc...
But before you start modding do a standard maitenance tune-up which consists of:
Spark plugs (can do upgrades right away)
Clean throttle body
fresh air filter (if you are keeping the stock air-box)
Oh and check this out.