951B 86J1706 Engine Serial Number Identification

Good Evening,
I am new to posting on here, so here goes nothing!  I recently purchased a 951B with water in the oil.  I purchased it knowing this as my dad and I rebuilt a D6C 3306 motor a couple of years ago and this seemed like another good project.  My first thought was this was just a 3304 so it would be similar to the D6C motor we had already been through.  Upon doing a bunch of reading maybe this is a D330 motor instead of a 3304??? it seems they are quite similar from what I have read, but is there a way to tell for sure?  The tag on the left hand side of the block reads 86J1706, a picture is below for reference.  Any help identifying would be appreciated.  Thank You

86J1 to 86J1991 uses the D330C engine, for runner and very similar to the 3304. Unfortunately there are parts that are not interchangeable.

Thanks Old Magnet!!! I dropped the head off this morning to have it looked at. I may have another question or two before I have it running again, Thanks