I continue to have a plug fouling issue, I just replaced my 770 holley with a new one and still have fouling. Here's my setup:

454 .040 over
roller cam .600 .600
MSD 8501 cap, coil (with rev limiter on module)
Accell wires
timing 14 initial, 36 total
Compression -about 8 5 to 1
15" vacuum at idle

I am running R44T plugs and they foul if I idle for any period of time. Smells rich at idle. Float levels on carb are good and I have adjusted for max vacuum with idle adjustments (I am 1 1/2 out on the screws.

I suspect a weak spark or maybe too cold of a plug. Anyone have any suggestions on plugs and a gap? Also, my Accell wires measure 1000 ohms per foot , is this a problem?

Thanks,

I have a very similar combination with my El Camino. 454 w 8.5 compressions and 049 heads (same as 781). I run R43TS plugs. I had a terrible time keeping plugs in it. After 1000 miles they were junk and had to be replaced. I put a MSD 6a in it and the problem was solved. Same plugs last for years now. I think the mutiple sparks at low RPM's really help the combustion process.

Thats what worked for me anyway.

Does your car still smell rich at idle? I am going to test the ignition tonight. I strongly suspect a weak spark.

Also going to run an R45TS and see if that helps.

It did before the MSD. It would make your eyes water. Now it doesn't at all. I hid it up under the dash and you can't see it either. But you can hear it buzzing. The M22 drowns it out though!

The Bosch platinums work really good.
I use to pull my 70 chevelle out of the garage quit a bit in the winter to work on friends cars.(Needed the room). Stock plugs would constantly foul out. Switched to Bosch plugs and aint looked back since. got em in my 69 right now. since then alot of my buddys have switched out for the same reasons. I wouldn't recommend em with NOS but who knows.

RB.