erratic idle and running issues

i am very confused with my engine, i have jus done the headgasket since it was on its way out and runnin abit odd. i have put it all back together and now my car is definantly not running right!!!!!!!!
the car is idleing at 1500rpm on tick over, the idle and air screw are half a turn from being fully in! the distributer is fully retarded to try and get the revs down as well! but still idleing far too high which meant i cant time it properly. when the car is coming to a stop as well the engine just dies (guess this is due to the timing being fully retarted) the timing marks on the pullies are spot on and the spark side of it all is spot on :roll:

i havnt got a clue where to start and really need help!    any ideas?

Is the butterfly definatley returning to idle position?

Could be the gasket underneath the carb!

i have got a new carb gasket but that didnt change anything but i havnt actually checked the butterfly, i will check that this eve! cheers