Stop in for a cup of coffee

The back half should have the p/n and assembly date stamped here.
View attachment 1715421114

IIRC There's usually one digit difference between the assembly with the pulley and without. You can look in Hammtracmk Historical Library for a service bulletin about this.

Casting date for the back will be on the 'ear'. This one was sandblasted.
View attachment 1715421115

Might be the same location oin the front halfs.
edit: Yes. see mmcdetroit.com/ICCA/References/Engine_Compartment/image_32.html

Well, it is not much point of looking for the date on the one I have as it will be too new anyway since it is a square back. Then it is hidden too since the part no and date code is towards the inner fender and impossible to read.

Bill