The rod should stick out of the transmission about 1" or a little more. The cable housing has a large-diameter section that allows the rod to go into it about another 3/4" or so when the throttle linkage goes to full travel. If the rod is sticking out further, you'll need to drop the pan and see what's going on inside. It's a very simple setup- - - -the ONLY thing the cable does on a 350 is initiate the full-throttle downshift. The modulator controls the shift points.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!