I'd say if your class is limited to an old fashioned stock Briggs flat head block, yes.
Then everyone is on the same level playing field.
If you allow any engine as long as it's 14.5 CID then the flat heads are at a distinct disadvantage in the HP dept.
An OHV has the potential to make way more HP than a flat head.
If you allow any engine such as billet blocks then it gets even more impossible to make that kind of HP with a flat head.
If you limit the displacement to 14.5 CID then a Briggs Animal block will have the best life expectancy.