Thrust Bearing- Abnormal Wear
I had a thrust bearing looking like that,, only it was a little blue in color from heat..
It was a marine engine that had an OMC outdrive on it, Apparently they have two diff length imput shafts for the outdrive,, this one was too long.. Boy did that motor stink, literally..
Perhaps check the 4-speed to see if it's one of those you're supposed to trim the tip off the trans imput shaft, if the crank wasnt drilled for a 4-spd,, Perhaps the shaft wasn't trimmed quite short enuff,, and is shoving the crank forward... just a thought..
hope it helps