vibration at 65-70

[Walts_restoration]

When i drive my 83 2wd c10, i get a vibration at roughly 65-70 mph, but when i drive 60 its fine and when i do 75 its fine. At first i thought it was the road, but now im not so sure. I cant remember if it did it with my other set of tires or not (just put new wheels/tires on the truck from another truck entirely). I went from cheapo passenger car tires to a decent set of lt tires, same size wheels 15x8 rallies. I know the rubber of my carrier bearing is going bad, and when i put it in gear i get a clunk (its an auto), but it almost feels like the front end is where the vibration is coming from and not the driveshaft. Also has new monroe gas magnums, so i know its not the shocks. Should i get the wheels balanced? they looked balanced but i didn't have them done and it was on my parts truck like they are on my own now. Or maybe an alignment issue? but I would think alignment would be a constant thing if it was off. Thoughts?