Hi,
I pulled the carb this morning and took the float bowls off. Everythinbg was very clean as you'd expect from a brand new carb with no signs of debris. I checked the diaphram for the vacuum secondaries, which again, was fine.
I've checked the distributor cap and that is OK with no signs of burning.
The advance is mechanical and that is nice and free with no sign of binding.
I have good fuel pressure (around 7psi) at the carb. I'm running a Holley electrical pump with a Carter mechanical pump, as recommended by KMS.
The MSD has a 6,000rpm limiter fitted.
The plug wires are Accel Hi-Temp Super Stock Spiral Wound with separators fitted.
I'm still inclined to think it is fuel starvation, but I don't know where the restriction is.
Here is a picture of the plugs. There is a pretty wide variation of colours with 5,7 & 8 looking almost unused and 3 looking pretty sooty.
Thanks again for your input, it is appreciated.
One more point, I have a manul on rebuilding Big Block Fords and it recommends separating plug leads 7 & 8 to prevent induced firing. Do I need to take this into account with the plugs leads I have? The leads have been run adjacent to each other as suppled by SA, but they are in clips and don't actually touch.
Paul