I don’t know what is expected from a low compression short block, usually 7.5-1 cr and a reproduction 375 hp cam. Save your money unless you can put compression and cam in it!
You don't need mid/high CR to make power, airflow makes power cr just squeezes more out of it sure 10.5 or even 13.5+ would be better but no reason you can't make 400-450+ hp with reasonable mods.