Holley instructions contradicting on fuel bowl level ??

In my experience, that's pushing the limits. Definately put the smaller 110 needle in the primary bowl and/or get a pump with return spring that keeps pressure below 7 psi.
I hate to spend your money, but I think that's worth it. There's not a lot of options for fuel pumps on LA engines with the '70 up waterpump. I found good pressure control and volume delivery using Holley's 'Keith Dorton' 110 mechanical pump, but its over 10 years old. I'd like to think new ones still the same internally, but I don't know that for sure.

Nice thing about the clear sight plugs on your fuel bowls is that you can see if the level has risen or fallen since you set it.
If you do need to dump some fuel out of a bowl in an emergency, back off a bowl screw and drain it into a sardine can or whatever. I've even had to use a rag - hardly the best the choice but prob better than dumping on the engine.... :(

I do have another .110 n/s that I bought. I could install that, but i'm not sure how much it would bring the pressure down when going from .120 that is already installed in the primary. I'll look into getting a different gauge like the other fella suggested.