Yep, synthetic fluids, efan and exhaust upgrades will be good ones for starters.
Synthetic fluids throughout will help your equipment last longer, extend drain intervals and keep stuff cleaner, longer. More resistant to thermal breakdown and sludge build up as well.
Efan, allows the engine to turn more freely without having the mechanical fan. Better mileage, HP, and smoother idle.
Exhaust - here again, frees up some backpressure and allows the engine to work less harder. Don't free up too much backpressure or you'll sacrifice low end torque and gas mileage for sound. Don't mess with the cat converter unless it's plugged. IMO, the days of removing cats are over unless you have an engine setup pushing out high HP numbers. -Mike-
Daily Ride: 98 Ranger, 2.5 Auto, K&N CAI, Flow 40 exhaust, reg cab flareside, grey metallic, 235/70R15 Bridgestone A/T's
Other Ride: 05 Harley Electraglide, tc88, Screamin Eagle stage 1 kit. Chrome lowers, nastalgic bag guards, black cherry, 1965 Electraglide Emblems