Couple of things since this is going to see street use with what's likely later-model drivetrain:
Speedo cable from Imperial Services will adapt a '63 speedo input to the later trans output.
IIRC it's a '66 Charger cable?
And the E-brake cable setup may be different: I don't recall on my '63, but my '64 was (both had later rearends).
Use headers for a 440 not a 383; the 383 ones exit into the trans crossmember and require a length of S-bend to clear.
Watch the lower ft corners of the front fenders for tire interference, depending on your setup; I had to trim them back at a 45 angle, about an inch.
A 285/70R15 on 15x8 Ramcharger rim will fit in the rear, usually need to narrow the rear axle a bit, if you want a tall (31") tire for the highway.
Early Bs are 22" radiators so cooling requires a little thought and certainly a fan shroud; clearance is pretty tight.