Ok then what is the recipe for a 425-450 horse streetable 340

I have a '67 Valiant with a 340 dated 1-21-71 and a 904 trans. dont know if stock converter or not. I dont know current c ratio but want to bolt what ever I need to get as close to 450 hp as I can. What is the cheapest way to go about this. I was going to get the heads I mentenioned in my earlier post. What do you guys think.
I want a good all around street and very occasional recreational strip rod.

P.S. I know the color sucks but for $750.00 (for the running and driving car) I did not complain. I'm thinking a matte silver like the one in Mopar Muscle. I love that car.