I am planning on bumping the jets and adding a #4 washer as you have done. I have never done a rejet and wanted to clarify a couple of things.

You are replacing the slow jet, right?

Did you replace the o-rings on float chamber?

Sequence seems to be:
Pull carbs
open vacuum chamber pull needle, shim and reinstall
open float chamber, replace slow jet, reinstall cover
then put carbs back in

Anything special you ran into on the way?

Thanks, Dan