bucking and surging at idle

[metalgod]

80 full size k5 blazer 350 with no emission equiment on it at all. it has a holley 600 cfm carb eletric choke, petronix flame thrower dist. and coil.......................now to the problem this truck when at idle surges at a stop light, in drive it lerches the truck, if you then put it in neutral it stops or barly hold the gas down it will stop lerching....but the idle is not set to low and when its surging its not to low...now this morning while warming it up (btw hot or cold it does this) it was surging so i poped off the air cleaner (i had suspected the choke was stuck) and im just watching the engine rock from side to side so it messed with the air screws and the idle......nothing no change!! so i put it all back to where it was and here i am begging for your help........this is my girl friends truck and shes out beating the crap out of my truck untill i figure out this problem so help me swiftly please....sorry about my spelling