Anything that a V8 responds to, a V6 will too. Best places to look are in the air and fuel department. Better heads, better compression, better cam, better intake, better carburetion, and better exhaust.
How much? Well, you can't do the funny math like ricers like to do. You know, this intake is worth 30 hp and this decal is worth 10 hp and this rear wing is worth 15 hp, etc.
It is the combo package and they all feed off each other. I'll bet on a mild V8 engine, if you did all of the above, you'd probably see 40 or 50 hp out of it. With a V6, figure 75% of that.
But my favorite way of making a V6 stronger is with turbochargers. Look at the Buick Grand National. Nothing wrong with that engine.
