It's a budget thing, it depends what you want to spend or can afford too spend, Dart steel heads are about $700.00 good heads for the street or racing (you will have to drill the steam holes in the heads if you do a lot of street driving) decent cam, intake, carb and headers and you're looking at around 450 HP, all for less than $2,000.00 in parts.
JMO
Zip.