would carbon knock be my problem ?

[blazer2007]

Still on the hunt for my knocking noise as I posted about maybe a cracked flex plate. It is a knocking noise not a ticking noise. http://www.67-72chevytrucks.com/vboa...newthread&f=24 I have the engine apart and see nothing wrong with bearings, no bad cylinders etc. Cylinders still have cross hatch ,everything looks nice ,only about 10,000 miles or less on rebuild. Only thing is there alot of carbon on piston tops and inside the heads on the valves. When I got the engine he talked me into a eddy 1405 carb which I was always fighting to get it to run good ,too rich then too lean. Was going to switch back to the Rochester when the noise happened. Do you think the carbon is my smoking gun for noise. There is no marks on heads or piston to show it was hitting. I,ve done everything . I had the motor running with no torque converter or pullies and belts. Only other place would be mech fuel pump which showed no noise with scope when running, timing chain showed no marks on cover, replaced dist. oil pump I don,t know if that would make that kinda noise. Will get to heads and also re-check bearing clearance's after I clean up my mess and make some room. Just looking for others insight and opinions. I just want to know what the heck is making this noise.