as others have said..
the 400 cid rods are shorter than the other small block rods you need the 5.7" rods..
the other is yes to balance blueprint, not needed but if they are decking the block they'll need to do some of it anyways..
if they line hone the mains remember you'll need a shorter timing set..
if the heads have the valve job already done. leave them be..it's to late..
save your time and money and start saving for a set of vortec heads (299 each complete)
with your rods your pistons going to be so far down the bore, decking the block would do zero..
I know you want to use what you got, but you need to go over this build again..
your rods are 5.565" way to short