Relly Weird Ignition Problem

[pbatura]

Greetings, Ya'll.

I've got a problem with a '76 that I initially thought was due to bad plug wires, but after changing them, twice, and checking the timing, I believe there is something else afoot.

Thinking about how to diagnose this, I realized I could use a timing light to determine if the plugs were getting juice. So, 30 minutes ago I connected it up and found that cyl 4 & 5 are not "lighting up."

When I initially changed the plug wires (Accel), I also replaced the coil with an MSD Blaster, thinking that perhaps the original coil had finally given up the ghost. Outside of this, I have done nothing else to the ignition.

I inspected the distributor, and there seems to be some play in the plate ("rocks") that may be causing the gap to fluctuate, but the spacing between the advance/retard pickup coils and the reluctor seem otherwise OK. The cap tests fine for continuity, and with the plug wire connected, amd getting from 10.2k to 17.4k ohms resistance, so I know the circuit should be good.

Oh, and one other thing, I converted to SUs from the EFI, with carbs having been adjusted according the "Just SUs DVD."

Any ideas would be greatly appreciated.

Best regards,

PSB

[pbatura]

OK, do I really feel stupid...

Figured out that I had two (yes 2) dead spark plugs. These were new Autolites, so didn't expect a problem. Getting NGKs tomorrow.