Originally Posted by Frank Reiner

The camshaft bearing journals of the M110 engine become progressively larger in diameter from front to rear. As a consequence, obviously, the camshafts cannot be removed through the front of the cam box. As I noted above, the cam box will have to be removed from the engine to remove the cams, when the engine is installed in the chassis.
In the case of the engine being out of the chassis, the cams may be withdrawn rearward without removing the cam box from the engine.