RE: Tee Dee .049/.051 venturi
'Tis good that you are having success with your venturi modifications.
Girl friends could be more complicated . . . .
Just as an aside: A Fox standard 1/4X32 long plug can be modified to serve as a TeeDee .049 venturi.
The "post" has to be knocked out and the resulting hole drilled out to an 1/8" , or so.
The threads are the proper size and there is a relief above the plug thread in just the right place for the fuel from the needle body to flow around the plug/venturi.
You just have to drill some small fuel feed, jet holes in the relieved area.