Have been cleaning the block up a bit before it goes to the machine shop. It has no numbers, just two holes drilled where the numbers should be, It is a "D" casting. I have not measured bore or stroke to verify that it is a 425. Has anybody seen this before? Maybe a factory supplied short block?
I posted this on the TOA forum as well, but I thought the bigger audience over here might be able to help.
Thanks!

 

There is nothing on the shelf behind the water pump just to the left (facing from the front) of the oil pressure sensor? The numbers there are cast into the block and thus cannot be removed by unscrewing and removing a metal plate. If it is a 425 from 1966 or '67, there should be the number 389244 followed by a capital D in a larger type size. If your engine is from 1965, the number would be 381917 or 386525, at least according to this page

http://tech.classicoldsmobile.com/36.shtml

 

Oh, Yeah,
It is the right casting to be a 425, 389244D and it looks to have been in there a long time, as far as dimensions, I meant I haven't measured it for overbore or had it apart to check rod size.
I was more curious why there are no numbers where the "numbers matching" VIN sequence should be, like is that common to short block replacements, is it a previously stolen motor, Etc.
I don't care if the numbers match as I intend to build it as a driver, not a show car, I've had enough of that to last me.

 

The older motors, 64-67? Had the ID numbers stamped on the front of the heads.
If you still have them, check them out.

 

Heads are at the shop already. Will check when I get them back.
Thanks!

 

Olds did not use VIN derivative stamps until the 1968 model year. The last 425 was cast in 1967.

 

If those numbers next to the distributor follow suit with the 455 numbers,then that block was cast January 10th,1967,which would be the 4th year of production.You figure that they started casting the 425 in 1964,for the 1965 model year.Maybe I am totally wrong.