The 268S cam is a great choice, but small port heads perform better with single plane intakes. Think stock 273 4bbl, marine manifolds, Holley street dominators, Edelbrock streetmasters, or a real find, the torker 318.
I agree, but the truth is the stockers dont have enough plenum for a good turn and eveything else is too large or unobtainable. Not to mention the lack of gearing in this car and therefore limited rpm. Hence my choice.