Help with Yenko block engine no. please

[GMH454]

Was moving storage yeasterday, and dug out the Yenko block from under the bench.
When I loaded it into the S/Wagon I noticed something on the engine pad.
Upon further srutiny it was a clear stamping of :-
TQ524LB5275126 (the Q may be a O)

Now I know that Traco and Greenwood stamped numbers into their cars and engines but the numbers were small 3 to 6 digits etc.

That is a a lot of mucking around for a shop number stamping. I mean Yenko did not make a million engines, so why such a long number.

Sure its a simple explanation, would anyone kindly share.
Not sure this will help, but it is one of the bigger Yenkos, with "YENKO" cast in the block.

Terry