Yes the one @Otto identified at the back of the block, to the left of the frost plug behind the camshaft needs a threaded plug. Mine has a threaded Allen key plug.
The one on the exhaust side of the block to the left and above the C6DE also needs a plug. I have a square headed, pipe threaded plug in mine.
The one on the exhaust side of the block to the left and above the C6DE also needs a plug. I have a square headed, pipe threaded plug in mine.
