It was running fine then started running rough like it has a vacuum leak but can't find anything. At stop signs it tries to buck and snort and generally wants to die. I know it is something simple any suggestions?

 

Is it stock or other? Mine is an 87 S-10 with 350, and a pretty good sized cam, and when run a bigger cam it drops the vacuum at idle but increases at driving speeds, also having the same issue with my truck, runs great for a few miles then misses and dies, replace the plugs and its good for a few miles and then dies again and i have to replace the plugs, cant just clean them, my problem is carb related, its running too rich and killing my plugs, so thats what mine does, dont know if this helps, good luck!