Are you sure you have the floats dead nuts?
It would seem that you could get that big 2.9 to run fairly close with the 52.'s. I know it has a lot to do with cams , but I run 70's with my 2.5
No smoke and smells like a carbed motor in the garage-umm-yep. Not trying to a smart ass, but I think it is hard to judge anything that way. Not sure you will be able to idle a Mikuni fueled 2.9 in the garage without stinking a bit.
Like Jon said, turn the pilots out a turn and see what your LM2 says.
What's the condition of the carbs-especially the pilot screws?
Hopefully your gauge will be okay. I know for a fact that a blown HG kills the sensor. It will probably act erratic if it is bad.