starter grinding

OK, and I thought that I had mentioned to you before, but it was on another site.
OK the early 904 had two converters. Engine does NOT make any difference.
From 1960-Early 1962: 11", narrow ring gear, no weights, 1.550" pilot, slotted hub 18 splines. 148 tooth ring gear.
From late 1962 to 1967: All the same as above, except for the >>> 122 tooth ring gear<<<
Just a point: The hub is the part of the converter that goes into the pump, and the pilot goes into the crank.
This should tell you which converter you've got. Personally I think you've got the Early converter.

Hope all this helps you.
Sorry…I stand corrected on the descriptions. Yes…small pilot… with Pat Blais’s adapter ring to large crank. I may have the 148 tooth ring gear converter. Like I said, I just picked this one out of a friend’s pile not knowing the 2 different tooth counts.