So I finally got my 327 to fire up and run, Sounds really good, minus it runs rich. When I rev it, 2000-2500 RPM it shoots black smoke out the tailpipes. I have the floats adjusted to the bottom of the sight holes, I tried playing around with the mixture screws, I messed with the distributer, ( NO vac. advance) I dont know why its running so rich, the carb is brand new out of the box. 750 Holley Double pumper mechanical secondaries. Any ideas???

Only thing that worries me is my valve seals. But wouldnt oil cause blue smoke??? Thanks in advance for any input.

 

Too much carb for a 327. 750 with mechanical secondaires, so I'd guess it's a double pumper too? Should have gone with a 600 cfm vacuum secondary, or a 650 cfm vacuum secondary.
Might be able to re-jet it to get the idle circuit to clean up a little.