Just turned 500 miles on my 64 Sport Fury. Motor is a 69 440, MW clone, with a 63 model crossram, with a pair of 1405 600 cfm Eddys. Just pulled the plugs for a look, and a compression test, showing 150 psi all, except one 145 read. I admit, my first 440 (like that's any dif), first crossram, first dual carbs.... Okay, what I'm looking at, on the plugs, strap mark is almost to the base. Plugs too hot? Using Champion J12YC plugs. I'll get a few pictures up, later today, after my camera gets charged. Ceramic is tan, it's full length. One plug (#8) slightly oiled, but after finding the plug boot on the wire cooked pretty good, that is probably that problem. Both carb mixture screws are 1 1/2 turns out. Engine runs fairly strong, pulls good, no smoke out the exhaust. What I am getting out the exhaust...is soot! At a little over 400 miles, it started showing, so during the last 100 miles, or slowly building up over time. Carb mixture too rich??