79 sa s4na swap running rough
 

i have a sa with the s4 na swap i was driving earlier and she started running rough got it home checked plugs they were dirty cleaned them up spun the motor with the egi fuse out and put them back in with no luck checked for vacuum leaks nothing checked the cas its good. when its running i have to keep throttle or it will die also spits and sputters with a bit of greyish (dark smoke) out the tail pipe what else could it be? Coils? plugs? Wires? im at a lose here