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.

I put a complete drum to drum 8-3/4 rear from a 65 Plymouth with the floating drums in my 63 and it fit and works good. I actually put it in my 63 before I bought it as my buddy owned the 63 and I always worked on his cars for him as he had me swap the rear in when he owned it before I got it. I also went to a newer (1970) auto 727 trans and got rid of the ball & Trunion and went to standard type U-joints. Rear leaf springs are the same ones as some A-bodies use as the ones in my boys 72 Dart are the same as the ones in my 63 size and lenth wise. But I use 3400 lb rated SS springs as he uses the 3000 lb 002 & 003 SS springs in his Dart. Its just a few things you can change or update to if you like the later drivetrain from the mid 60's to mid 70's. But the changes I made were simple and easy and I am 100% happy with it. Ron

Somehow I thought that the push would be for the A body. Is there a 1 7/8 header that gives easy clearance for plug removal for the '63?

I run TTI 2" headers with Indy EZ heads that have angled plugs. But they are all easy to change. If the eng is cold I can change all 8 in about 15 minutes. If its hot you have to be careful not to burn your hand or arm of course. Ron

I have a friend who try to buy some adapter cable shifter parts for his 1963 Sport Fury from Imperial Services, nothing but excuses and problems after being billed on his credit card, BUYERS BEWARE of them

Sorry to hear that, Cab - my experience with them was several years ago and went perfectly.
The cable itself did the adapting, so if it's the '66 Charger cable as I seem to recall, that should be available elsewhere.

Unlike a lot of you I tend to go with smaller/lighter cars.. have I owned
A and B-bodies long ago.. but even then I still went with lighter cars

so, a 6.0 LS and a 250 shot?

Lol no I’m a Mopar guy for life sitting here with 2500.00 worth of nitrous stuff and storing it in my spare bedroom