This is a pic of a DT 413 six....
The engine block has extra lower reinforcement to support the crankshaft journal webbing.
Also adds extra stiffness to the block in general.
Seven main bearings. Tocco hardened crank, Nickel Chrome Molybdenum block/head etc. Hydraulic lifters.
The design of this engine looks similar to the large displacement engines of the 30's that Chrysler built.
The Chrysler straight eights... 323, 385 are designed very similar to the above moly block 413.
The 385 had nine main bearings...the 323 had five.
The 413 shown above has seven main bearings.
3" main journals.
This engine weighs right at 1100 lbs.
When I can get to it I'll load some pics of the Chrysler eights...