First time Holley tuning help

66s and a PV plug?
That's your problem right there!
I have a bit of a cam in my 360 too. It likes 72s and a PV on top of that!I think the front PV is marked 10.5
I think I have 80s in the back, with no PV (it's a DP) back there.

With your tuning skill level, I would back up the bus, a long long way.
That means defeat the Vacuum advance. Defeat the secondaries.Get the T-port synced up (see below). Leave the PV plug in the front, but put at least 70s in there.Put the acc pump back to stock; that is one of the last things to mess with. Put a vacuum gauge on it with a hose long enough so as you can EASILY see it from the driver's seat.This is how I do it.
Take it for a short ride on a deserted road. Get it into second gear and up to 30 mph minimum, and over 1800 rpm. Then gently roll into the throttle, and watch the gauge.As soon as the engine complains that it's not getting enough gas, note the vacuum. Repeat this at least a dozen times until you get the hang of it.That vacuum reading is where the PV needs to be already delivering some fuel. So start with a PV that is marked for that vacuum. Make sure it is not open at your idle vacuum.How will you know? Cuz the engine will be slowly flooding itself to a stall, or you will need to keep blipping it to clear it out.
Now here's something I have discovered; the numbers on the PV may not behave as you might expect them to. I bought a really nice PV tester, and tested my collection of PVs;some new/some used. They were all over the place. So I just numbered them from earliest opening to latest opening, and started road testing.
For a streeter you can balance an early opening PV against a small MJ, to get better gas mileage.Or a slightly later opening PV against a slightly larger MJ, for a bit of snap when off the PV. If the AFR gets too lean as the PV comes on line, you will feel the car slow down during the transition. Too fat is really hard to feel, so I work from the sag to just getting it gone.
What you are striving for is a linear power delivery below about 3000rpm, with no lean surging, and no fat mushy low speed driving and no tendency towards stalling at idle.
After this you can start feeding more and more pedal and higher and higher rpms until you get the primary MJ dialed in.I would quit testing when it takes full throttle to 5000 without going lean.Yes the primaries will go to 5000, if the fueling is adequate. They will go as far as the valve springs go, with the right fueling.Yes you can try 68s; but then you may have to try a different PV timing.
Ok so that will keep you busy until next week.
That's how I do it.Yes it's time consuming and a PITA. But it's one change atta time and that makes it hard to get lost, and you won't end up stuck saying What do I do now. You will be either backing up one step, or moving ahead one step.
Remember, at this time we still have no Vcan hooked up and no secondaries yet either.And the #1 thing was the T-port sync/timing..
If it ever detonates, you have to back off immediately and revisit your timing before moving ahead.
Or you could just go to the Holley sight, as mentioned.