Jet suggestions for Carb Re-build

[jimeast]

As mentioned in a previous post, I plan on using a 3310-1 Holley 780cfm in a 482 stroker rebuild, and would like feedback on starting point for Jets and Power Valves.  I know the jets and power valves are more likely than not to change during tuning, but am curious if someone has done a similar build and can suggest a starting point for the jets and power valves to use in the rebuild.  The engine is for a '67 Mustang Convertible

Note:  The 3310-1 has a power valve in both the primary and secondary metering block.

Mustangtek list a number of 780CFM carbs for various engine combos, Primary jets run, 69,70, or 71;  Secondary jets 83.  Power valve 65 or 85 (no listings for 3310-1 with two power valves) 

Engine Build:
Block:  427 stroked to 482
Compression Ratio: 10:1
Heads: Mildly messaged Felony heads by Blair Patrick
Intake:  Blue Thunder MR
CAM: Hyd Roller, Lift .520, Duration 276 total, .224 at .05 (Symmetric)
Exhaust:  Will use CJ cast iron, or FPA headers

[My427stang]

A 3310-1 would originally have 72 primary, 76 secondary, 8.5 PV primary, 10.5 PV secondary per my documentation

I'd jet it stock, and I doubt you will have a vacuum problem with that cam unless it's very late, so you could start there, but my gut tells me 6.5 PV front and back would work, or block the rear PV and go 72 primary 6.5 PV at the tightest, 84 secondary, plugged PV

[Drew Pojedinec]

Yup, 72 front and 82 back (pv plugged) is a good starting point.
Downleg 3310’s don’t need much to be right.

[jimeast]

Are there any benefits to trying to use and tune the secondary power valve?  Seems like it adds complexity, and maybe little benefit for a street engine.

[Drew Pojedinec]

I’m a marine engineer by trade. I always view less parts as less points of failure.
No reason to not use a secondary PV if you would like

[My427stang]

I ran my 489 with a 1000 HP series vacuum secondary with a modified early 1850 primary block, double downlegs and an 850 BG base.  I ran either 84 square with 6.5 PVs front and back and 84 primary / 90 secondary with a block off.  The block off ran about the same, never dyno'd but couldn't feel the difference and when you are in the throttle, you are at low vacuum, so the PV should be open.  I can't see a time when a vac sec would be opening and you are at high vacuum allowing the PV to be closed.

IMHO, plug it in a vac sec, one less thing to come uncovered, blow, or be mismarked