There were some changes for 67 that a 66/67 expert would have to let you know to make sure none of them will be an issue making the swap. 67 was supposed to be the debut of the 472 but they pushed it back a year to complete the million mile testing. One difference I know of was the intake was made for a Quadrajet. The heads were also different because they used the pedestal rockers that the 472 ended up with. Not sure if any of those changes prevent swapping.
The oil pump timing cover issues are better covered in the Buick world. Basically the main body of the oil pump is the aluminum timing cover so if/when it wears the whole cover needs to be replaced. At one time there were people bushing the Buick covers, not sure if that is an option for the Cads or not. I think there is also a possible issue with one of the water pump bolts caused by the dissimilar metals between the block, bolt, cover, and water pump. The covers often get damaged dealing with that one stuck bolt.
On the 472 they fixed the oil pump issue by making the engine block the pump cover and the main body of the pump was an external part. Many other makes the oil pumps were a bolted on assembly.
