[Mike_The_Grad]

Never seen one of those valves, that's pretty cool.
Another way to solve the over drilling on the plastic type of choke pull off is to get some delrin round stock or similar type material and cut it to fit inside a piece of vacuum tubing, then using a pin vise or jewelers drill set, drill the orifice you want in the round stock and insert it in the tubing that feeds the choke pull off. Cool thing about this is that you can have different pieces for different setups like at the track or the street.