if you have the original distributor, Rockauto has the Prestolite Pro-connect 118039 set on clearance for $8
I always just search for a 70 Chevelle or Corvette or whatever with a 350 and see what's on clearance.
Spark plug wires on a car are going through hell every day (700 degree manifolds, road salt, sub-zero temps in the winter, etc.)
On a boat, plug wires are in paradise (cool manifolds, no winters, enclosed engine room)