first a 292 cam will not work in a 230-250 motor the fuel pump lobe is not in the same location. if you have to buy new pistions get 307 flat tops they fit and are cheaper then buying 250 pistions.

head work for a low end puller just clean up the intake ports. the exhausts can use a little more work. as for carbberation. get a dual carb intake use to staged 2 bal. carbs the fuel distrabution is a big step forward.

you can go a little bigger on the valves.

get a copy of chevrolet inline six-cylinder power manual by leo santucci.