58-59 front wheel differences

[dsraven]

seen a 58-59 gmc (4 eyed version) that was parked for some time. there was no box but the cab and front end was intact and complete. it was a regular sized front end like a 1/2 ton (not wide fendered version) but had large diameter hole in the middle of the wheel on the front. anybody seen that before? I have a 3/4 ton but the wheels are just regular 8 bolt wheels. these looked like a current one ton dually would have but it only had single wheels out back. did they make single wheel one ton trucks in 57?