starting problemsPLEASE HELP

I have a 1978318 4bbl 600cfm and i just got a new carb and i put it on and it started right up and i drove it for abut 6-8 miles and i parked it and i tried to start it about 4 days later and it wouldnt start up . so i kept trying and it finally started then it just died so i tried again and it again and it did it again.and now it won't do it again.i tried to replace the spark plugs and it didn't help
the dristributor cap is fine . can somebody please help me?