1987 420 SEL Questions

I own a 1987 420 SEL and I have a couple of questions. I'm fairly new to the automotive world, so please be kind.

Is there a way (if any) to increase the horsepower? It currently has 201, and it feels like the car drags a little bit.

Also, is it safe to assume that acceleration will be better with in an increase in horsepower? It's good now, but I have a feeling it can be better.

I'm looking to increase the car's overall performance, so any other tips you can give will be greatly appreciated. Thanks.