Problem With Just #3 & #5 Cylinders, No Fuel ONLY in idle circuit. HELP!

[dirwin]

I'm pulling my hair out here with this IDA 48 set up.

Carbs are sync'd nearly perfect.
Verified floats are all set between 5.25-5.5mm
Idle jets are 65 in 120 holders
Fuel pressure is 2.5 pounds consistent.

At idle my header temps are all around 230-250 degrees 2 inches from the header flange EXCEPT #3 which is running 90-95 degrees and #5 which sits around 125-130.

If I hold open the throttle and bring the RPM up to 3-3500 RPM, into the main circuit, and stay there for 45 seconds or so, my header temps will all equal out at about around 340-350 all the way around, including #3 and #5.

What I'm fighting is that I'm very rich, it will run you out of the shop in no time, even with the doors open. All of the plugs are Motorcraft 32 heat range and all are very black.

I know that I'm getting fire to the #3 and #5. I'm running a mechanical advance MSD with 16 degrees initial and 37 total timing.

At idle, when the engine is warmed up, turning the A/F mixtures on #3 & #5 have no effect on the idle at all.

The engine is a new Ford Racing crate 302, 10:1 compression, Z304 heads with the Z303 cam. Cam specs are .552/.552 lift, 228/228 duration at .050 lift with a 112 lobe separation.

What I've done so far:

verified correct float levels
removed idle mixture screws on #3 & #5 and blown them out (lightly) (no effect)
swapped the idle jet holders and jets from #3 to #4 (no effect)
swapped the idle mixture screw from #3 to #4 (no effect)
verified that the accelerator pump shooters are working on all carbs, including #3 and #5

I'm really struggling with this so any suggestions would be very much appreciated.

Dave