The nozzles I’m using are a little bigger than stock, but I believe I also drilled one another step larger so will try that.
(And I believe moving to the top hole could bring the shot in quicker too).
Check the bore the metering rod piston rides in. Piston too.
I had similar problems, back in the day, when I was using a TQ. They were easy to find in the wrecking yards back then, so it wasn't a big deal.