10C105452/V08200NR (should be V0820CNR...
350/300 with a Turbo 350 from a 1970 full size car assembled at the Southgate, CA plant. The engine was assembled on August 20th, 1969 at the Flint, Michigan plant. Yes, that block "should" be a 4 bolt main so it looks like someone at Flint screwed up!
And by the way, there was no Impala "SS" in 1970. 1969 was the last year for the SS and it was only available with a 427.