Carb and intake will make a nice upgrade as far as performance. Shouldn't be too expensive either. Keep your eye out for a used Eddy Performer and a 600cfm Holley/Edelbrock. To save a few more bucks, i'd run a nice dual exhaust off the stock manifolds, much less hassle. Run as much initial timing as you can and it should be a nice cruising package and get as good or better mileage then stock. Jmo.
