Ok, so youre saying the car is running rich just sitting there???
If its rich at idle you need to check:
-float level ... ( thats good you said )
-the idle mixture screws
-the condition and rating of the PV
thats it,
-the jets DO NOT CHANGE IDLE MIXTURE
if they do, then youre idle stop screw is set too high allowing the throtle blades to be held open and causing the carb to run on the transfer circuit / primaries instead of limiting it to the idle circuit.
8 is very low vacuum for idle. (i think thats about what my dads dragster made...) Most good street motors I have seen still pull 10-12 at idle and mild street motors can be 14 or higher...
Are you sure you have the cam and ignition timing set correctly?
Dave-