Larry,
You don't mention what type of turn signal switch you have, factory or after market add -on. Bill will probably correct me, but I believe that 1958 was the last year for OPTIONAL turn signals. What made me wonder about this is your mention of "4-way flashers," which were NOT stock on your truck. The "SignalStat 500" was the most common in its day and there a couple of reproductions around now. There is wiring diagram for this unit in our "tech Tips" I believe, or if not try a Jeep electrical site.
best wishes,
Les
