i did a full port and 70% polish and i did that at 45k and agine at 48k and every thing is OK
i did have this problem after i cleand the TB with a WD-40 and ACDELCO chock and carp cleaner

the problem goes away by itself after a week or so and the high idle goes after 2 days just keep the truck to idle for 2 houres ...

i use to do this: when it sticks at 2000 rpms i switch the ignition from on to off to on fast ...it idles at 700 rpms after that ...try it out

 

hey bro just seen your post didnt read all sugestions but I have had this happen on the gen IV trucks. Fix is engine-idel airflo-air flow min. take this table and keep scaling it back by say 10% and eventually you will get a grip on your idle and pushing through the red light/ stop signs. Hope you have HP tuners and hope you didnt polish directly under the throttle blade good luck