hi guys ive recently changed my head from a hybrid to eseries with a au head gasket. i started it up and it idled fine, then i went around the block and stopped at a set of lights and sat at 1200 rpm?? i got back and played around with the idle screw and hasnt changed it?? any help will be appreciated

If there is no change with the throttle position screw, try unplugging the idle speed controller and see how that goes. Otherwise I'd put it down to a vacuum leak somewhere. May take a while to locate if that indeed is the problem . Listen for any hissing noises and/or use starter fluid to spray where you think it may be leaking and listen for changes in rpm.