Running a 400 big block? ?Then whats your combination?
As far as bearings go the selection for 400's is limited. This is one of the reasons many guys have the block machined to accept 440 cranks, much better bearing selection main bearings + the longer stroke. As far as strength go's the 400 is by far the strongest mopar big block. Stock 400 cranks are all cast so if you want a forged you need aftermarket or 383 as they had forged.
I would say the 400 in stock stroke would perform much the same as a 383,likes to rev due to the short stroke but can use good breathing heads as it has large bores.
Heres what I would do to a stock 400.
4bbl alum intake
largish solid cam
heads that can support 280-300 cfm
forged crank
lightweight hyper pistons
aftermarket lightweight rods
balance to 7000 rpm and good solid machine work to square it up. The 400 block is one of the worst for core shift so have it sonic checked.