318 2 brl to 340 4 brl conversion Whats needed?

It's a start on the basics.

Kickdown linkages come in two basic styles: The single-rod linkage and the three-rod linkage. Single-rod linkages tend to be model specific. The three-rod linkages are more generic. The easiest way to get the proper kickdown linkage is to find one in a junkyard. Unfortunately, many 1970's era Chrysler vehicles (i.e. Dodge trucks) are getting hard to find in junkyards (junkyards are full of Chevrolets for some reason) especially if you live in a rural area. You are also out of luck if your car did not come with a four-barrel option. So I put together a (not comprehensive) listing of the parts needed for the three link style kickdown linkage. (Parts are from 1983 Car manual unless otherwise noted.)

top linkages
4287 969 Throttle spring bracket
4287 969 Throttle Cable Bracket with top bellcrank
4041 548 Upper rod (carburetor. to top bellcrank)
4027 590 Spring (upper rod to carburetor)
4041 420 Middle rod from top bellcrank to bottom bellcrank (A727 transmission)

4041 509 Middle rod. (A904 Transmission)
3870 666 Linkage assist spring (middle rod to top bellcrank)
3751 531 Stud for bottom bell crank
3751 535 Bottom bellcrank (A727 transmission)
3751 529 Bottom bellcrank, (A904 transmission)
bottom linkages
3769 198 Spring, bottom rod
4027 374 Swivel, bottom rod (connects to trans. throttle lever)
4173 225 Bottom rod for 318 with A727 trans. (will for other applications with a little blacksmithing
4171 978 Bottom rod for 318 with A904 trans.
3820 193 Bottom rod for pickup trucks, 360 w/ 727, (Obsolete)