ADDING A 4BBL..HELP Please !!!

You will need kick down cable several available such as Lokar universal type or Mopar factory type this one which I currently have that bolts right up: http://www.bouchillonperformance.com/BPEtkdc.asp shop around.
Additional items:
Carburetor throttle lever adapter for Chrysler such as: http://www.summitracing.com/search/Department/Air-Fuel-Delivery/Section/Carburetors-Accessories/Part-Type/Throttle-Lever-Adapters/?Ns=Rank%7cAsc

A manifold to carburetor adapter plate.

Some sort of throttle & kick-down cable mounting bracket and return spring to secure cables to engine & carburetor.

Perhaps some plumbing alterations to adapt fuel line to new carburetor.

Don’t expect to get any appreciable performance gain by tossing on a 4V carburetor on to a stock engine. Chances are good that a 4V will cause drivability problems on that stock engine.

In order to get performance improvement you will need to modify the stock engine and exhaust. The more changes one makes to improve engine’s ability to breathe the more performance can be extracted from a slant.

Changes such as increased compression, oversized valves, enlarged exhaust system, non-stock cam shaft, distributor advance re-curve are needed, and drivetrain alterations should be assessed such as rear gear, and converter stall. Any changes must be well thought out to work in harmony with each other or the result will be a pig in a poke, and a ton of wasted money.

If you want best bang for the buck shoot for a Super Six factory setup, basically a two barrel carburetor, and enlarged exhaust. This will perk up a stock engine, with easy bolt on parts.