need help with 347

[badnewsranger]

i have a 347 and im having carb issues. not sure if im posting this in right area. the problem i am having is that the motor runs fine at idle and all the way up to when the secondaries start to open. then all hell breaks lose. im getting pops of white smokes up thruogh the carb. first thought it was a timing issue but after going back and forth from 0 degrees of timing to 30 degrees a liitle i at time there is no difference. now what i have is a 347 and that is about all i know. it came with a full size i bought a few yrs ago. it was built an never fired. the guy didnt know an give me any of the motors specs as far as cam or anything like that. and it has a model 1406 edelbrock carb on it i had it running good with no problems. ran beautiful. but i stole the carb of it for a month or two to run on something else and now that it is back on im having thease issues. upon reinstalling it got new base gaskets. i have been pulling my hair out and can not figure it out. i have tried timing, metering rods, metering rod springs, i have pulled it all apart to make sure there is no dirt or anything stuck an everything is as should be. im sure the timing is not a hundred percent but i know its close cause it idles smooth and runs perfect up until about half throttle then it will pop smoke and continue reving up or pop a couple times and die. any advice and or help would be much appreciated. also if its a need to know im running the gm style single wire hook up hei distrinutor which is is also new