Hi J. After owning a new 7-77 I would say a 24x12 is a bit small on that engine! Maybe your 999 would like a 25x12 or... You can use the throttle linkage with a bit of modification but do replace the pivot point rivets. They are way too sloppy. I am not sure of the choke catalogue number, but it must be the one for the Gemini 160. If your Stearman is not cowled, you can get to the idle adjustment. Make a long thin screwdriver from a push rod by filing the blank end and screw the threaded end into a drilled dow rod for a handle. You can only adjust at high throttle position with the engine off of course. At least you can get to it without removing the engine. Your comments make this thread rewarding. Thank you. -Tom