Your 45 might not be as responsive with the oval port heads.
You might want to look into slight porting your round ports and
cleaning up the dags, especially the exhaust short turn radius.
Some rallye guys I met in the past praised the round port heads.
It all depends what you are after as beyond this even if you gain
10% more using oval port heads your pockets might say enjoy it as
it is: a well balanced and fun streeter.