Off the top of my head, here's what I would do with the 40's.
Try a 34 venturi, maybe a 32. Use a main of 120, and an air corrector of 160, on an emulsion tube that you have. I think F11 is common?
Idle jet something like an F8-50, or 55. If the idle mixture screw wants to be very close to seated when adjusted for smoothness, lean the idle circuit, and vice-versa. One and a half to two and half turns off the seat is good.
The combinations that will work are almost endless, so the best thing is to just try something and get a baseline.
Part throttle driveability is all in the idle/transfer circuit, a big bog on opening is a poor transition to the main, which may be the venturi choice, and top end rich is air corrector, rich in the main overall is main jet.
Have fun, be patient, change one thing at a time.