Right now my M715's NP200 is in my '63 J300. I'm getting ready to fire it up, so I went to fill up the TC with gear oil. The old gear oil came out brownish, but very clean. I put my finger inside the drain hole and I noticed about 1/8" of a muddish substance.

I have filled the 200 with gasoline to hopefully dissolve the residue and plan on flushing it numerous times before I put gear oil in it.

I wonder if this may be a factor in the overheating issues these things suffer.

Mikel