The highest resolution available would be the ?format=jpg&name=orig photo from the original tweet:

https://pbs.twimg.com/media/GUBYMb0WsAAurC9?format=jpg&name=orig

Not sure if this resolution is any higher than the one already posted.

Also some interesting followup info: https://x.com/elonmusk/status/1819597689283121225

The amount of work required to simplify the Raptor engine, internalize secondary flow paths and add regenerative cooling for exposed components was staggering.

As a result Raptor 3 doesn’t require any heat shield, eliminating heat shield mass & complexity, as well as the fire suppression system.

It is also lighter, has more thrust and has higher efficiency than Raptor 2.

Truly, a work of art.