I've built several different combinations of 400 stroker motors for pump gas and race gas.
I would bore the block first after having it sonic tested and then decide on the piston and rods and compression ratio with your current heads, bore it as big as needed to straighten up the bores only.
Don't go to the maximum bore to start with If it will clean up at 4.360 use that, if not it might clean up at 4.375 or it may need to go to 4.380
My current bracket motor is a 230 thick main cold weather block I bought from Andyf and it cleaned up at 4.350
I have had several new 4.150 BB stroker cranks with Mopar rod journal sizes offset ground down to 4.300 stroke with 2.200 rod journal sizes and used forged steel BB Chevy H beam rods in 6.800 and 6.700 rod length The pistons are really light and the motors make a hoop of torque and HP
The more common crankshafts available are 4.25, 4.150 and the old shorter 3.91 stroke, they work very well also, especially for a pump gas motor
OP, good luck on your build, be ready to enjoy or have the crap scared out of you the first time you go to WOT
AKA aside, these motors can make a bunch of power is built correctly for the application so be safe until you get use to the new found power