How about some suggestions for relatively inexpensive, simple engine mods to increase horsepower - not too drastic - ? Any help will be greatly appreciated.

Assuming it is stock, I'd say start with a good set of long tube headers, oversize cats, and a better exhaust. It will make a difference you can feel in daily driving and give you a better sound. Possibly a good upgrade of your intake - lower restriction, cold air, etc.

I would also start with the things Lee listed and after you have that done you can get it dyno tuned to also free up some extra horses.