Bitter learning curve. Absolutely DONE with carburetors!!!

I had the same thing in a fresh 360 but with Mechanical fuel injection on Methanol which lead to a catastrophic engine loss. We set up way rich which we learn how to tun it so as not to burn pistons and it started to not want to rev, became hard to turn over, oil pressure dropped and finally could hear a knock over the open exhaust. I had spun a rod bearing killed the crank journal which in turn led to a .010 bend in the crank. The rods are damaged from the bearings and there is metal through the engine which took out couple of cam lobes and lifters and managed to find there way into some piston skirts. I had the gray sludge you mentioned in the valley and the oil pan. This cam from fuel dilution in the oil washing a couple of bearings clean. Pull you oil pan and check your bearings before your's looks rooted like mine. I will be going to a carb from now on.
Cheers
Tony