Check this first.
Take the carb off. See how much transfer lsot is exposed on the primary side.
Also if any is exposed on the secondary side - shouldn't be. But sometimes people wil l crack the secondaries open to get more air at idle and then they go to far.
Write this all down and then go make some reference notes.
Turn the idle positon screw (stop screw) so it just touches the throttle.
Wite down how much, if any of the t-slots are exposed.
Give it a 1/4 turn and measure the t-slots again.
Keep going until you have a reference up to .040"
Set the t-slots at .020" or .025" and put the carb back on the engine.
Get it running. If it's too low of rpm to stay alive, give more more throttle and keep track of the number of turns.
If you can't keep it running with the t-slots in the .020 to .040 range, then adjust the intial timing and idle fuel mix.
If it needs a little more air to get rpm up - then crack the secondaries. If that works - then you can drill the throttle plates.