Open up your carbs and see what size main jets you've got. From there, you gradually increase the jet size to match your freer flowing exhaust.

Raising needle jet is mainly for fattening up the midrange. Changing the main jet will take care of this plus the top end.

 

With the hole filters you may want ot jet arround 170 175, I would start with 180/185 and jet down if you need to. Running rich only fowls plugs running lean too long will burn pistons.