We are putting a supersix intake on the slant in the grandsons duster and a 2245 holley carb. I

See this thread for kickdown options.

And yeah, you'd do well to find a more appropriate carb; the 2245 is bigger than optimal for a near-stock Slant-6. A well-chosen Carter BBS, Holley 2280, or Bendix-Stromberg WW3; or the Rochester 2GV used on 318s only in '71.