Ah my apologies, had G54B/4G54 on the brain and overlooked you had a G63B (aka 4G63 without jet valves).

Here they've got a 4G63 bare head without cam or valvetrain:
https://www.cylinder-heads.com/produ...e-cast-ch124n/

This search should bring up their other 2.0L heads for the D50/Ram 50; one's a full rebuilt head, but the others come with valves/springs only:
https://www.cylinder-heads.com/?s=mi...ct&dgwt_wcas=1

I gather the Astron 4G52 2.0L was never offered in the States for these trucks, so those should all be Sirius 4G63 2.0L heads, but may wanna contact them to confirm anyway.