Any suggestions on this problem are appreciated, no matter what they are.

Cylinders 2,3,5,and 8 are misfiring on my 302. I have stock single points distributor with vacuum advance (brand new), Holley 4160 600cfm carburetor, electric fuel pump (regulated to 3 1/2 psi), no electronics at all, and all of the ignition parts are brand new. The truck ran great for a few weeks and then started to ping while cruising at highway speed. After re-starting the engine to drive back home it started missing at low RPM. By the time I got home it was a dead miss on 4 cylinders. Here is what I have tested/tried/set:
-Dwell 30 degrees with .019 point gap
-Timing 6 degrees BTDC (vac adv blocked)
-Compression above 115 psi on all cylinders (120 avg.)
-Less than 10 psi difference between cylinders (lowest was #1 which is not missing)
-Fuel pressure is ok
-rockers are moving (likely not wiped cam)
-#1 is at TDC with rotor at #1 on distributor (because of this I believe timing chain is ok)
-disassembled carburetor, no problems found
-swapped around plugs and wires, no change (firing order correct and missfires did not follow plugs or wires)
-no vacuum leaks
-new gas

The only patterns I see are every other cylinder on the cap and that the 4 cylinders share the same plane on the intake (lower).

I know my Big Blue can't be the only Ford in the world that has had this problem. Any help is greatly appreciated, the truck belongs on the road not in the driveway.
Thanks.

 

what is your vacuum reading.should be 18 to 20 with stock cam.

 

My vacuum is about 18" at idle. The cam is a "B303", actually this whole engine is out of a '85 Mustang GT, I just scrapped the fuel injection a couple of weeks after I put it on because of computer problems and the fact that it is next to impossible to get accurate diagnostic info for the TBI 5.0 H.O. system.
I just changed the condensor today and when I started it back up the outter ring of the harmonic balancer fell off. I guess I did not notice the rubber was so torn up. Hopefully maybe I was just too stupid to notice the outter ring moved and the timing jumped because I neglected to tighten the dsistributor hold down, but that is most likely wishful thinking.

 

so you should be using the ho/351w firing order then with that motor. are you sure the dizzy was set correctly at 0 tdc. with vacum advance plugged timing should be at 8*btdc. are any spark plug wires crossed,damaged or just plain old. what type of spark plugs are you using.

 

I have Autolite plugs. I can't really check the timing right now because of the balancer, but I hope to have a new balancer in next week (had to play with my buddy's new SKS, didn't have time for the junkyard).
I did however note my lack of a ballast resistor. I am not sure but maybe I have been having problems with the points due to the voltage being too high for the points and coil. I am going to try a new coil, points and condensor with a ballast resistor installed as to step the voltage down some. When I wired it up I forgot about the ballast, I have not exactly been able to think "old school" for a long time since most vehicles I work on don't even have a distributor.
I am hopeing that running the constant 12v killed the fields on the coil and all of my problems will go away next week. It sounds like a real shot in the dark, but a true "old school" guy told me this could very likely be my root of all problems.