How to make Horsepower?

Just about anything you do will add HP to the sleepy slant, BUT a turbo with about 8-10 lbs of boost...now you're talking fun...
almost everything else is too little gain for the relative expense.

As for stock
Depending on what you read, 95-110HP is stock, BBD ,HEI and bigger exhaust gave me 125 on the iphone dyno app