A set of aftermarket aluminum heads ( take your pick of the heads available) will have smaller combustion chambers and better flow along with less weight. So if they are in your budget they offer multiple benefits toward your goal. An aftermarket dual plane intake like the Edelbrock airgap, an appropriate 4bbl. carb of your choosing and a camshaft that puts the power solidly in the range the car will driven at are keys to getting the most out of your combination.
Choose your entire combination before you buy any parts. Consult with "experts" to be sure your combination is optimized and compatible with your goal then order parts.
Chasing a number might result in choosing parts that are too "big" resulting in a motor that might make the peak number but at the expense of power loss in the rpm range the car will be driven at with your choice of gear. Think of it like this, for every hp gained by moving the peak hp up out of the rpm range it will be driven at multiples of that hp will be given up in the rpm range you will use it most. Using that mind set might keep you from choosing parts that are too " big". Good luck with your project.