Chrysler CD8 engine ID question

I have been offered an engine presented as a 1931 CD8 Deluxe third series engine. How can I be sure that is what it is? I do not have the third series engine # info. What other markings could I look for?

Thanks

John Baker

John: The engine number should be above 15000. I don't have my book handy to give the precise starting number for deluxe blocks. Another thing is that there are more webs on the side above the pan line than on the 2 early series blocks. Another way is to remove the head. The bore will be 3 1/4" and not the 3 or 3 1/8" of the 2 earlier blocks. Sherwood Kahlenberg Sherwoodk@aol.com