Do you know the compression ratio on these 2 engines, 300 & 420? I would assume 10:1?

I am satisfied with my 3.0 L. How about you? What were some of the pros and cons of this engine.

BTW, thanks.

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'89 420 SEL
'90 300 SEL
'68 Olds 88 Convertible
'84 300 SD (sold it)