Just returned from the boat ramp, motor ran totally fine. Did a couple of tweaks to the low speed needle as usual and dialed in the low idle but it held 850-1000 RPM in gear submerged all the way up to the exhaust relief holes. Obviously ran better when it was trimmed up and could breath the right way.
Guess the old carburetors were just plain wore out because they had already been pulled apart, new gaskets, cleaned, etc!
Thanks Don