Re: how to increase horsepower in my 98 V6.
Most people start with intake and exhaust. Then you can go cam & springs/retainers, roller rockers and other head work like porting and polishing. At that point you'll greatly benefit from a tune so pick up HP tuners. Though can be beneficial earlier along the road this is where the tuning starts to become more important. After that go for the power adder of your choice be it nitrous or forced induction. Its usually cheaper to buy a v8 car or drop in an engine from a donor to get the 3.8L up to the v8 power levels.
96 3.8 5spd, highflow cat & muffler. Upgraded rear to torsen diffy, discs and 3.42's (unfortunately not originally on my car). Next: bushings all around then clutch then front shocks/springs. Then saving up for an l26 and spare trans to build up for when needed/wanted. Hoping to keep it going for another 10 years.