79 300 SDT trannsmision linkage adjustment
 

The linkage adjustment on my 79 are two cables which one adjusts which gear. I started messing with them the other day they were both very loose thighten got better shifting from 1to2 but then it's very quick to 3rd with a flare unless I back off the gas pedal. Any help woul be appriciated.

neither cable adjusts any gear......

one is a manual idle speed control adn the other goes to the cruise control actuator.

assuming what you are calling a 300SDT is actually a 300SD