I have a 1983 GMC 3500 1 ton 2wd with a 5.7 350 with a 600 cfm holley carb. I am having no luck in getting this thing to start she is getting plenty of gas air and spark but seems to kick on for 2 or 3 seconds then stalls out again. I need some help anyone got any ideas. This truck was running less than 3 days ago then the carb was pulled off to be drained of bad gas that was in the tank for the 3+ years it sat out back.

 

more than likely the carb needs pulled apart and throughly cleaned also check for vacuum leaks