Challenger340 said

NOT that it matters, just TRIVIA,
Most "Strength" issues got covered,
but,
a few things may have been missed in the 400/440 block strength discussions ?

* Although nominal Sonic Test Cylinder Wall dimensions are Identical from Lowdeck to Bigdeck, the SHORTER cylinder wall 400 gets the nod for greater Rigidity by having less unsupported length.
.700" ain't a huge deal, but every little bit helps to maintain Cylinder wall Integrity for sealing.
* 400/440 main caps are identical "outside" dimension, just the 400 is "thicker", due to the smaller hole drilled in it ?
Again, not much,
But,
Sad but true with stuff made outa Detroit "wonder metal' Cast Iron, more mass is better.
Finishes the case for Grinding the 440 Crank Mains DOWN to 400 size and keep the thicker main caps !

I like the 400 Blocks better period.(IMO)
Stronger Mains
Stronger Webs
Stronger Cylinders

If you don't wanna spend the Money to have the 440 Crank Counterweights "Machined", get out yer Angle Grinder, takes about 2-2 1/2 Hrs,
then a Mild Clrc in the Block, easy-peazy if yer handy.
Anything in a 451 under 700 hp I do 'em this way.

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