I have rechecked the plugs, looked for vacume leaks, and readjusted the rocker arms and still the exhaust tube for #7 cylinder has a slight glow in the dark (more than the other seven) Compression check told me that it is in the normal range. All eight plugs (the centers) look the same, slightly dark color. The motor does run a little rich though with this carburator. Put on the intake with TA's .062 thick intake gaskets. The intake is a B4B with a Holley 950 HP carburator. The only thing I can think might be happening is that it may be leaking from the underneath. Has this happened to anyone else? What is the problem, if any, could it be?
I have a problem with #7 running lean (plug was white compared to the others) changed the intake gasket and every thing else you tried o No: I'm leaning toward an intermitent leak in vacuum booster???
Did you have the block sonic checked before reuilding? You could have a thin cylinder wall. 455's are notorious for core shift.
Same motor that was in the car before I moved it over to the new frame. I had removed the intake to get it powered coated and installed a new TA intake gasket. I have looked at what I think is everything, but can't find a problem. I am thinking of removing the intake again. I was thinking it is rich, but the plug looks the same as the rest.
Staggar jetting will help. Im not sure the exact procedure but Norn Deile and I were having the same problem years ago with my engine
