Bellhousing 3945505 Does it make a difference?

[Italstalyon]

Cleaning out a shed and ran across a cast iron bellhousing with GM4 on the left and 3945505 on the right side bottom. Can't find a decode so I was wondering if it makes a difference what GM car I put it in....

anyone?

Thanks
Dave

 

[Rene Melten]

There is a casting # here that is real close...
http://www.tracyvette.com/bellhousings.html

 

[fbody_mike]

Take a look again, you sure that 4 isn't a 2. 3925505?