Running rich....To big of a carb or?

Hey guys,

Before I get into this...I hope it doesn't turn into a big debate over brand preference. Just looking for some helpful info to guide me on what the issues might be.

First of all...1972 plymouth Duster, has a 67 318 engine,bored .030 over to a 323 , purple shaft cam (not sure of specs...but has a mild thump to it). Dished pistons,long tube headers,eddy performer dual plane intake,2.5" true dual exhaust, proform electronic ignition, 2500 stall converter, transgo tf2 shift kit,4.56 gears out back,28" tall tire. Street car mostly for cruising....may see an occasional day at the track.

I am currently running a new summit racing 750 cfm electric choke vacuum secondary 4 barrel carb.( basically an old holley design) ( this carb http://www.summitracing.com/parts/sum-m08750vs ).

I know some of you might be saying "to much carb"....but I have seen some running as big or bigger with great results (even on smaller cubed/somewhat stock engines)......but this is why I am here....for some knowledgeable info from the carb guys....not assumptions.

Here is my issue, It starts great, it runs great,it idles great, it revs up great, It comes on like a bat out of hell. BUT it runs realllllllly rich! It will burn your eyes while its running, puffs black smoke out of the exhaust while running ( mostly at idle....but does it during a rev also) if I rev it up a few times and then get out of the car and look behind it I can see wet patches behind the exhaust on the ground where un burnt fuel sprayed the ground (it will also spray anything behind the car). I pulled my spark plugs today and every one of them was pitch black and reaked of fuel. I cleaned them up and re installed them (they only have a few hours of run time on them over the last couple of years since I have been restoring the car).

I am trying to work out all the bugs in the car and get it finished before I deem it road ready (restoration is about complete).

My timing seems to be good, starts good and runs great, my ignition system is all new ....I dont think it is spark related.

My question is....is this just purely because this is to much carb for my engine?.....or is this something I can tune into proper working order?.....if so.....what should I do?. I tried adjusting the floats once before and I got them to about the middle of the sight glass on each feed. I have tried balancing the carb out before...I still cant get the rich issue to go away.

pretty embarrassing when you hop in your nice restored "new" car and fire it up and it looks like a tired jaloppy puffing smoke out the tips lol.

Id hate to go and buy a new carb if I can no doubt fix the issue some how instead.

again....I know this can be a touchy subject....I know everyone like certain brands and can list of part numbers for all sorts of carbs they recommend. But I dont want it to turn into a debate thread lol. just looking to see if my current set up can be tuned in or if I should be looking at down sizing to a lower cfm carb. It runs great is the thing....no bog or hesitation. it just runs rich....I also am worried that if I downsize carbs to say a 600cfm to get rid of a rich condition...that I will loose some of that seat of the pants power it currently has.

sorry for the long post everyone. Just trying to explain it all to try and get an accurate as an answer as I can. Thanks in advance