Retune my entire carb after installing new heads?

Doc,
At cruise you are quite possibly getting nozzle drip from the secs because of the high rpms at cruise. You may not realise this & have adjusted jets etc accordingly to get the mixture 'right'.

At cruise the carb jets, air bleeds etc are calibrated on the air & fuel delivery from the pri bores. You now have a substantial amount of air passing by the sec boosters as the air makes it through the bypass air holes, possibly enough to pull fuel [ unwanted ] from the sec boosters.

This is why it so important that large amounts of bypass air is not routed through the t/bores, but through the body & exit under the blades. The bypass air then does not interfere with fuel metering.