Welcome to the site. Nice truck. You have, what looks to be, a worthy truck (but I say that about all of our trucks). We cant say much about it without realizing all the greased over details. NAPCO 4x4 are certainly more unique than the 2 wheel drives, but I would not trip over the rareness of NAPCOs. It is special for sure, and nice to see preserved, but not 1-of-a-kind special.
We all would be interested to confirm with you the original nature of the truck and specifically the drivetrain. We can do that in the driveline forums.
As far as your mods - You bought the 4x4 for its special nature and it is what it is. As soon as you change that suspension all bets are off. That being said it is your truck and you drive it the way you do, so those choices are yours. If you make long trips and often then it may be worth making it more comfortable. If you like to take it to local cruz ins and otherwise make shorter drives then that should dictate the changes you make. I enjoy driving a mid 60s, 4x4, as is, but I drive it with regard for the nature of the original purpose of the truck. I make some longer trips to be sure, but frequent stops are planned and I dont worry about the music - cant hear it.
I would also be interested in how loud the truck is? Would mods be consistent with the noise I suspect you experience?
