My 68 Hemi RR is about 65 miles away at the moment, so I'm just gonna take a few shots from memory:
8# is low, thought they were more like 15#. I don't recall for certain what's on mine but it's the OEM reproduction.
Shop manual has the body info; no separate factory manual (as in GM cars) that I know of.
Ground strap runs from rt cylinder head to firewall, uses same fastener @ firewall as the other firewall items. IIRC, some repro straps are incorrect length but otherwise appear OK.