I'm old enough to remember late 50's and early 60's gmc and chevy tandems hauling stone from the quarry near my home when I was a kid. some of the gmc's were 671 diesels(will always remember that sound) but the chevys were gas V8s for the most part. There was a 59 chevy tandem cab&chassis on ebay a couple years ago. as I recall it was in either Georgia or N Carolina and from the pics it sure looked like a pulling tandem and not a tag axle. it was painted a faded green and looked to be a fairly solid old truck. Maybe it's still out there somewhere.