Mopar made three different 426 Wedge motors in 1964, a 365 HP street wedge,(came with flat top cast pistons) a 415 HP Max Wedge and a 445 HP Max Wedge that came with domed forged pistons. They stop making the the 426 M.W. motors in either late February or early March and started putting the 426 Race Hemi motors in the last Dodge and Plymouth they had firm orders on for the M.W. motors. My point is you do not want to use the forged high compression pistons in a used block with a ridge on the top of the cylinders. They offered the street wedge in both 1964 and 1965 and stop making the 426 wedge blocks for passenger cars after the end of production run in 1965. They alledgly made a 426W race block later for NASCAR application, never confirmed one way or the other by Mopar
I had a 1965 street wedge block bored to 4.320(stock 440 bore size) as it was bored to 4.310 already and had some taper in the cylinders, that motor ended up with a 4.25 stroke crankshaft and a set of Eagle 7.100 long forged H beam steel rods with a set of custom Ross piston to lower the compression down to 9.5 to 1 to run California pump gas with iron heads back in 2001 or so It ran fine on pump gas and made close to 500 HP on the DTS engine dyno in Ontario, CA ran by Vrbancic Bros.
I didn't want to build that motor as it had two external freeze cracks in it and a casting flaw in the bottom of # 4 cylinder that had been seeping water into the crankcase since day one The customer insisted on fixing and using it as he had a 1965 Plymouth Satelite 426 street wedge motor car and that block casting date was proper for his cars scheduled production date
As already mentioned your bare block may be worth more than a complete decent running 440 to a restorer or restoration shop
Good luck on your project, keep us informed on what you do please