Is this the Shitstar engine?

2005 GM V-8 with DOHC is a Northstar.

If any valves touched and pistons, I'd go grab a decent used engine to either use for parts or to swap in.

Well, any rate, if junkyard engine or rebuild, make sure you research the Northstar forums for better cylinder head reinstall so your head gaskets don't **** themselves again.

I've seen dealers drop the whole sub-frame assy with engine/trans and struts still attached just to fix the blown head gasket issue.