hi i pulled a head off an xf carby today and i noticed it had HF-10 stamped on it anyone know what it means?

Its a casting thing.....some have HF7, or HF5......I had and XD with an XF engine that had a HF7 head on it. HF7 are ULP too.

the HF stampings means its alloy head XD-XE, XF models had C1, C2 E1 and E2. C = carburettored models and E = EFI models while late model XF uts and vans from 1988 when the EA was being made had the D stamping, D = C2.