Budget 318 build

Use the car to take the family to the park. I always used the classic cars for a "fun" day. Heads is where your gas mileage and performance will be made. I like your idea of porting and cutting the 318 heads.
Nothing wrong with 318 heads on a teen. Want to get there fast? 360 or a 408 stroker. Get back to basics with your teen with a 4 barrel and dual exhaust. It will work well with your stock converter and gears. It's easy to over cam teens and then you need a $1000 worth of converter and gears to make it work.