Engine date of manufacture Glider

How do you find the engine date of manufacture on a rebuilt engine. Not the remanufacture date but the original date.
Just read FMCSA info on gliders or other trucks with older engines. They have changed the date for ELD requirements. It now goes by the engine manufacture date not the truck manufacture date.
If the engine is a pre 2000 it does not require an ELD even in a newer truck.
I am trying to find out the date of manufacture for my series 60 Detroit. I have the remanufacture date but am having trouble finding the original engine build date. The stickers on the engine are for the rebuild.
Been looking online but haven't come up with anything yet.

 

There is a serial number on the rebuild tag but I haven't been able to come up with anything from it.

 

The 98 emissions does not mean 1998 manufacture date.
The new 98 emissions engines were being made till a few years after 2000.

 

My truck has the 98 emissions engine but I don't know what year it was made.