Here it is, the Holley Numerical Reference.
It'll tell you what your carb came out of the box with.

You are right about the idle setting. The standard idle screw setting for Holleys is 1 1/2 turns out from lightly seated. It shouldn't be more than 1/4 turn on either side of this for a normal street engine at close to sea level.

Study the Numerical Listing.
For the 3310 there have been at least 11 dash numbers. Most of the 3310s came with 72 primary jets. Holley carbs have usually been close out of the box. If anything they usually were a little rich. The secondary plate number can be referenced to equivalent jet sizes although it usually doesn't have to be changed. The combo of the plate size and the power valve rating take care of the top end of the fuel curve. At wide open throttle the exact A/f ratio isn't as critical as long as it doesn't go lean.

I'd start with 72s in the front. Run the carb and see what it feels like.then I'd start decreasing jet. Holley says go down two jet sizes at a time. So swap in 70s. If it still drives OK you may want to swap in 68s, but that is pretty far off. If the jet is too small the engine will exhibit lean surge at steady speed. Some people disconnect the secondaries while working on the primary side. If the carb shows lean surge with stock jets then you'd want to go up two jet sizes. Once you get close you may want to fine tune with a single jet step.

If you have an A/F meter so much the better.

I live at altitude, between 3400 and 5290 feet. On my first carb I had to go down 6 jet sizes before it stopped fuel fouling the plugs. I was really surprised when I went down to Phoenix in the middle of summer. I expected to have some trouble with leanness. Surprise! Everything ran fine at 110 degrees. Looking back on it I imagine the density altitude was sky high so my jetting worked.

R.
Others will have much more advanced answers for you.