I have found that the secondaries are fairly close on the 3310. It might be prudent to wait and see how close the WOT is before you drop the coin for the secondary block.

The primaries are another matter. The PVCRs are way small, which puts the mains way big. Depending on a lot of factors ( gearing, cam, intake, converter, weight, speed, etc, etc.) the carb may cruise on the idle circuit or on the main circuit.

I would suggest that you drive the car with the O2 awhile and see what needs tweeked. I usually need to step down the mains 4 sizes or so and open the PVCRs an equivalent amount, then go to a much earlier opening PV to cover the more distinct transition from the mains to the PVCRs. Something in the 9.5 or 10.5 range.

The WOT on the carbs are usually pretty close, it's the transitions that need the work.

Don't forget to dial the ignition curve in. If this is a big block, I have had the best luck idling with as much advance as possible and then getting the rest of the advance in as quick as possible.

I have used a lot of 3310s. They are the best bang-for-the-buck-carb out there.

Oh, and don't forget the secondary spring kit to tune their opening point. And a quick change cover is nice, but not necessary.