help ASAP

[83highsierra]

ok so im still trying to get the 305 swap complete in the c10 so i figured out the stock carb wasnt going to work because the motor was newer and had plug ins all over so i got on craigslist and found a holley(which i believe is a 600) and an edelbrock performer intake for $75 not bad. the carb and intake have been sitting for about 3 months. keep in mind i still have never heard the 305 run.... i put intake on and carb and its not starting it seems like it wants to but when it sounds like its about to it quits cranking as hard as it was.... also it seems the carb is full of fuel when trying to start it shoots flames straight out of the carb. i obvuisly am getting spark i put timing light on and it seems like im right on the money as far as timing. i just need help i wanna hear her live again...

thanks in advance