Engine identification
 

<style type="text/css"> <!-- @page { margin: 0.79in } P { margin-bottom: 0.08in } --> </style> I do apologize in advance if these are simple and rudimentary questions, however, I would like information about an engine currently in my Studebaker.

It is a 350 with casting number of 3970010
The head casting numbers match a 1970 LT-1 and the Holley carb numbers match a 1970 LT-1 Z28.

The engine identification pad in front of the passenger head is blank.
The casting date for the block is just a "3" with what appear to be x's or stars on either side.

The letters "T" "D" "N" are cast in the block near the casting date. There is a small arrow shaped like a droplet in the center with a dash inside of it

It has Cal Custom valve covers with an Edelbrock intake.

A large 5 stamped on the block near the fuel pump.


What I believe to be the case now is that it was a block from the factory made in 1973 with some 1970 LT-1 parts bolted to it.


Some unanswered questions are:
What does the TDN stand for?
Why is there a large number “5” stamped in the front of the block?
Why does the casting date have only a single “3”? Is that verification that it was a bare block from the factory in 1973?
Could this be an engine specially prepared by a known builder?
Is there anyway to determine the value of the engine separate from the car?


Thank you,
Chris