Ford Flathead Block Identification

@Austin kays

 

Great info! I just got another 49-53 Flathead that was pulled from a ‘40 Ford to do a Y-Block swap. This Flathead appears to have been rebuilt recently, has Offy heads and dual carb intake. The only marking on the block that I can find are passenger side , bellhousing area it has “H-284”. I can’t find any info as to what that indicates about what this came out of originally.
The car was running and driving when pulled, no leaks, no smoke, oil and coolant looked good as well.

Thanks in advance for any info on the block.