Glad to hear somebody is really using his old truck.
How do your plugs read after the trip?
Is the ignition/timing/carburetion all in tune?
Does the gearing run your engine within the power band of your cam at sustained rpm?
How is the coolant temperature?
If all is in tune, you should be fine with 44 plugs.
I wouldn't mix and match spark plug brands, but you probably won't harm anything.
