If carbs are off you will have 37 first pull, middle pull 44hp, and third pull 38hp...
This is probably very close on the numbers. A 650 cam, larger low compression pistons won't do much for you in the HP arena, and your carbs are stock, not "heavy breathers".
Never spend the money to make a vintage bike a "fire breather". Spend it because you enjoy it, love the final product, and disregard the fact that for 1/2 as much you could buy a brand new UJM that would put you on your butt through an intersection. Who cares, right? Its
yours and you have built it. At the end of the day, HP is about bragging rights, and its paper, not reality. Can you really
ride the difference?