“D” code 340 in 69’ Cuda?

Alaskan_TA said
2581 is 1969 model year......

Can you get a photo of the full serial number and post it?

It would also be good to know that casting date and to see if it has a full or partial VIN stamped on the passenger side pad by the oil pan rail.

there is no machined pad on the oil pan rail. Here’s a pic of the front of engine code