Holley 2280 throttle bushings

now i'm just having an issue finding a possible vacuum leak. I was trying to set the air mixture screws and started at 1.5 turns out and read you should slowly back them out then readjust idle and go till the vacuum stops increasing. Then work them in until the vacuum decreases and back 1/2 turn out. When i started backing them out i got to a point where the curb idle screw was no longer touching the carb base. so I went back to 1.5 turns out and was getting about 16 in Hg at 750 rpms. When i put my hand over the carb top the rpms increased which suggests a vacuum leak right? I used wd40 and checked both sides of the throttle shaft, around the carb intake gasket, where the intake meets the head, the 2 plugs in the intake runner #6 and the egr block off plate on the end of the intake (i used a new gasket with this too)

Engine is a 1971 225 stock, super six intake, holley 2280, timing was at 5 btdc and now is set at 10 btdc
I sprayed the throttle shaft ends with starting spray and SURPRISE they are the vacuum leak. The throttle shaft from a 318 Holley 2280 should be the same right?