Converting an L37 to an LD8
 

My friend has a 2001 Deville with 200k miles and blown head gasket. It has a "y' in the VIN so has the LD8 engine. We have the opportunity to buy a very lightly used 2001 L37 engine out of a Deville DTS for a good price. Now I know that I can't do a direct replacement without likely driveability problems. The PCM and transmission are different. However, I'm told that the engines are the same externally in terms of fit and from what I can tell the displacement, bore and stroke are the same. So what is actually different between the engines themselves. I'm thinking only the camshafts.

Specifically, could I take the put the cams from the LD8 engine into the L37 engine and install the newly cammed L37 engine into the car? Wouldn't that be exactly the same as the LD8? If not, what am I missing?

thanks