Marc, sounds like a shifter problem, adjust it first, if that does not help, then it may be worn out.
This is from the Hurst web site:
Q. What is the proper way to adjust my Hurst four speed shifter?
A. There is a 1/4 inch hole at the bottom of the Hurst mechanism that runs through all three levers. This is called the neutral alignment hole. To ensure proper adjustment, run the shifter from first into second and then back to neutral. Insert the neutral alignment pin (or a 1/4 inch drill bit) into the neutral alignment hole. If the 1-2 lever interferes with the smooth insertion of the alignment pin, remove the 1-2 linkage rod from the shifter and thread the adjuster button either in or out to eliminate the interference. Repeat this procedure with the 3-4 lever and reverse. To adjust the stop bolts, back the bolts out of the shifter frame until only a few threads remain. Push the stick firmly into third gear and hold. Screw in the stop bolt until contact is made. Release the stick and back the stop bolt out one turn and tighten the jamnut. Push the stick into fourth gear and repeat the procedure.
Hurst also makes a bushing kit with steel bushings to replace the nylon, called Pit Pak.
Hope this helps,