Trouble shooting my edelbrock performer carb please

OK so i have a 600cfm edelbrock performer carb with an electric choke and performer intake on a 318 with a pretty mild cam,electronic ignition, headers and 3" duals I just did a 2 to 4 bbl swap now i'll be the first to admit i am not the greatest with carbs. they are still somewhat new to me so i'm trying here. Sooo here is my problem. After i put the carb and intake on the car runs pretty decent but i'm having a starting issue. i have to start the car and rev the engine for about 2 min then after that the car will idle pretty rough like its going to stall bout after about 10min of running this way and when the engine starts to warm up it smooths out. then as i start to drive i'm experiencing a stumbling/bog from idle and on acceleration. Lastly i'm burning through gas like crazy and i'm running extremely rich. You can almost smell raw fuel out of the exhaust. i'm thinking maybe my jets and rods are too big and i should go a little leaner but i have hardly any idea of how to tune these things perfectly. The reason i say this is because maybe the engine is getting too much fuel when its cold and when it warms up it can handle the amount of fuel. Right now i have initial timing set at 12 degrees i was told i should prob go out to around 30-32 mechanical + initial timing but as for right now that is what i have it set at. I don't have any vac leaks i've sprayed around the intake and carb and there was no change in rpm. i'm not completely oblivious when it comes to cars i work on them for a living but our cars are alot different then the Hondas i work on everyday lol. Any help is greatly appreciated!!!!!
Shane