Plenty of stuff about the longer-stroke 250 on Google,for example:
roundtable.truck.net/viewtopic.php?f=17&t=4863
hankstruckforum.com/htforum/inde … ic=41764.0
I found these excellent articles in the CM archives about the Transcon, mentioning all the “odd” ■■■■■■■ 250 specifications Ford used, including the Super 252 (as they call it), the derated NTC250E and the derated E255 (I wonder if this was just a name Ford gave the NT240?):
archive.commercialmotor.com/arti … f-its-time
archive.commercialmotor.com/arti … ine-switch
IIRC, the original Transcon had a modified NTC350, called an NTC355.
Edit- just found this. I was looking for information about the Vine engine, and found a complete history of ■■■■■■■■ books.google.co.uk/books?id=JeS- … &q&f=false