Power estimate

 

yes I'm aware that there are different chamber volume heads used in AUS, the larger volume chambers were likely used on 351 engines, but still, not in the US

 

to complicate matters AUS also produced open chamber 351C heads

 

I recall a guy bought a set from an importer (I forget which one) & they were not a matched pair, date codes a decade off & chambers so different it would be foolish to use them as a set. seller wouldn't budge said they're not damaged & suitable for rebuilding so sale was good

 

here's a page to ID AUS heads while bolted on an engine, not complete but can be a help