['ol Pinion head]

As originally produced as '71 455 HO engines, there are
- 3 different 2 letter block codes,
- 3 different block casting codes depending on date cast
- 2 different styles of 197 casting heads, early and late...
- very expensive 455 HO specific Quadrajets that never go with an engine
- an expensive distributor, that came in 5 production dates.
...and there's more

Consideing what factory round port engines go for in nice rebuildable shape, Maxilo, you probably ought to be more specific with what you believe you need.