Google searching it comes back with a surprising number of hits to the HAMB. Lots of people seem to indicate you can use LA lifters in the early Hemis, they are close enough to work for flat tappets and hydraulic tappets. I don't know if there are any LA lifters with adjustable tie bars though, you may have to slot them yourself.
https://www.jalopyjournal.com/forum/threads/dodge-270-with-adjustable-rockers.565160/Also:
Now that you say that, they do look like a harley roller. Im not looking for a new set of these though. Just looking for .904 lifters that can be separated.
The bottom one looks like a Harley panhead lifter with the adjuster removed.
From what I understand, the last gen twin cam Harley lifters are LS Chevy pieces too.
