It's also likely that none of the linkage or the throttle cable are compatable with the carb that is presently on the truck. If someone cobbled some linkage together it can be replaced by the correct linkage as 3B mentioned. You should be able to fabricate a bracket to attach the throttle cable if you really need it. You can increase the engine speed with the choke for cold operation which makes the throttle cable redundant.
Fred


1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine