Hello CipiVTS
Maybe of no use, was there any sign of an oil light?
Check the oil level, then if me I would drop the oil, check pickup filter.
That would give you a sign, possible main bearings gone. (worst case scenario)
If all ok check the pushrod/bearing.
maybe lose alternator nut has worked lose
does not sound good mate, I had an engine seize on me, and is in bits at the moment.
I hope I am totally wrong, and I am sure some better advice will be along soon.
good luck
regards
TopiToo
[Edited on 15-07-1968 by TopiToo]