I have a 290 hp, 350 GM crate engine with a performer intake, patriot headers, and magnaflow mufflers. It's a daily driver '55 bel air, only about 20 miles per day. I'd like more horsepower, but I don't want to sacrifice drivability. I was considering going the cheap route, and just getting a set of iron vortec heads. But it's tempting to spend more on expensive aluminum heads, in the hopes for tons more power. But how much horsepower gain could there really be over the Vortec heads, 10-20 horsepower for an additional $1,000? I don't know. Thoughts, suggestions, advice...