Based on the supplied VIN number, the truck is indeed a 1957 F250 and the K part of the code makes it a 145HP 272.  The R part of the code has the truck being built in San Jose, CA.  Someone else will have to help with the block and intake numbers but looking at the casting date codes on each may help to clarify if that was the original engine to the truck or not.

Lorena, Texas (South of Waco)

Hi, new here. I have a 57 F250 and I'm trying to figure out if it's numbers matching. according to the VIN number on the door (F25K7R34935) it is equipped with a 272 Y block. The engine casting number is B5AE 6015 A. according to numerous online sources this is a 272 "replacement may have been used for marine or fleet use". I don't know if this matters but the intake manifold has the numbers ECW9425-B cast into it. I'm wondering if this is indeed the original engine for this truck.