Thanks guys,
The 750 has won a place in my heart anyway. It's the first carb that all I did was set the choke idle adjust and that was it. Nice looking spark plugs, good idle, plenty of vacuum, secondary spring was correct for my cars weight, no bog at low rpm or secondary transition, etc. And, it was still pulling hard at the end of the quarter mile. That 410 makes a beautiful engine for my 57 Fairlane, if it just weren't for the damned oil leak, can't stand that.