I have been running 400 block strokers since 2001. It was a 451 back then. Then I grew it to 471 (3.915" stroke). And in 2006 I prepared another 400 block for my 4.25" stroke 511 CID, and the other block is now a spare. I went low deck since it fits easier in the stock A-body engine compartment. Not was wide or as tall (hood) as a RB block. Also I feel the cylinders and main webs are a little less likely to crack on the 400 blocks. But you have to sonic check the cylinder walls at this power level and select the best thickness you can find.

I am using the aluminum main caps with ARP studs. Tall fill to 2.5" from the deck. This 511 has over 750 passes on it, I put new rings and bearings in last winter.