The numbers on the drivers side rear of the engine right above the bellhousing are more helpful.
part number after they machine it
A small or big block Chevy have a casting number on the top of the block behind the driver side head. MorTec has Chevy casting numbers listed online.
that would be the casting number of a Chevy 350
That casting number belongs to a 1971 Impala. It is a 400 small block chevy. These can be pretty good motors.
What Chevy engine block has the castin I mean casting number 397004
By the part number. Probably be a 39, series number.
Pass., side front.
On the left front in front of the head.
a small block 350 chevy
small block
This is the block casting number for a Chevy 305, build between 1976 and 1979.
I don't know of any visual differences between them, but if you look up the block number at mortec.com you might be able to find it. The block number is stamped into a boss on the block just forward of the passenger side head.