In any case you will need a V-8 center link to clear the oil pan and you may have to modify the engine mounts on the crossmember . Yes to V-8 centerlink. Either ger the LA mounts and isolators or the Schumacher /6 to LA conversion kit.
You will need Disc Brakes in the front . Use the late big bolt pattern spindle , upper control arm and rotor from a '73-76 A body . They were offered with a manual disc/drum master cylinder or power booster but you may not have room for the power booster with the V-8.Helpful but not necessary. If you go to BBP in front, something needs to be done to have BBP in rear.
You will need a mini starter also for exhaust clearance. Only if you're going to use headers.
You will also want at least an 8 1/4" rear axle with 10" brakes from an A body, 3.21 gears for all around driving. If the car has a 7¼" rear, yes. Mopar used 7¼ on 273-4/904 cars, but IMHO it won't stand up to a warmed up 318.
If your a 63-65 you will need a complete driveshaft made.See below
If your a '66 the driveshaft will be easy.If the 4-speed in longer than the 3-speed and/or you swap out the rear for a different size ring gear you will need to shorten the driveshaft.
Of course a floor shifter is the way to go and this will require a hump on the side of the trans tunnel.I drove an old Benz with 4-on-the-column a few times. Yes for the hump. You may want to consider a steering column with out a shifter in it.
At the very least remove the shift lever from yours.
And of course you will have to notch the drivers side cross member for the exhaust pipe. Only if you go to dual exhaust. Running the pipe under the cross member without a notch invites disappointment. An alternative would be an early single Formula S system.