Getting a smallblock to rev

Have been looking into a historic circuit race class down here in aus, considering running a 1967 Valiant, the class is limited to standard components with the exception of consumables (pistons, rings bearings etc..) cams, intake and exhaust are free as long as it was available before 1972.

The catch is here, the only small block mopar that raced here and is therefore ellidgeable in the class, was a 273 and auto.

Now I'm wondering, if we can make up for cubes, with rpm?

What have you all found to be a reliable combination that could suit our aim?

Thanks in advance,