Just looked at the right carb off of my 04, there's a hole through the port, connected to another hole into the carb, the way it seems like it should be, I've had my 04 since new and no one but me has worked on it. I'm sure it's stock.
On the 89, I'm thinking I should just drill a hole through the brass plug on top of where the choke hole should be, all the way down into the throttle body, then carefully drill another through the choke port on the side to connect the two, tap the top hole, and put in a brass plug.
Has anyone ever heard of this?