Hey Arch, You need to compare your old truck hubs to the car hubs and see if there are differences. A cheap pair of dial calipers may be all you need. Start by checking bore sizes and depths. You will also need to check the bearing width (or stack height) whichever applies. If you don't have dial calipers maybe one of the local bearing shops would provide some assistance, (like Bearing Headquarters or Precision Industries). I would guess that car hubs versus truck would be different.
If you don't get it figured out, send me an email, I work for a machine shop and would be willing to measure them for you.
Good luck
John
