440 Block salvage part info needed(Machine shop thread followup)

7.1 rods are long bbc rods. You would have to cut your cast crank down to BBC size, and then you would still have too much side clearance. They are intended for stroker cranks with side clearance adjusted for Chevy rods.
I like girdles, and I might use aluminum main caps on a 700hp stroker motor. A stock main cap 440 is fine to 6000.
Any quality forged piston will be fine, dish or flattop, depends on your deck height and chamber size. Time to do some calculating and make some combo decisions.
BTW, nothing wrong with a real Mopar cast crank in a performance application, be aware you need proper parts for external balance.