TVR Engine Number Location

[Esprit]

Just a quick question, but on a serp engine where is the engine number stamped? I know that there will be the original rover engine number stamped on the usual place on the deck face that sticks out between the manifolds of the middle two cylinders of the left bank but I also understand there's another engine number stamped on the front of the block somewhere starting with 37A....
Anyone know where exactly this is?

George