I have never seen a 235 with engine serial number LAY, and that code isn't in the service bulletin Tim posted, nor is it in the Vehicle Info Kit (original '53 Chevy factory specs and info) at the GM Heritage Center website. ( L- decodes to '53, A - decodes to regular service, and most RPO PG full-pressure 235s with block 3701481 have for the third letter either Q or rarely S, which designated power steering - both manufactured in the Tonawanda plant).

But searching elsewhere, LAY appears to be the code used for the '53 Corvette engine (full pressure 235, Powerglide, solid lifters/261 cam, etc). Scroll down at this link..

Nice find if that is correct!

Last edited by drdoug; 08/10/2020 9:17 PM.
1947 2nd-Series GMC FC152 3/4-ton
Follow the story in the DITY

1953 Chevy Bel Air Sport Coupe Powerglide