Want to upgrade trucks and wheels

What brand trucks and wheels are on the current Walthers Gold Line ore cars?I would like to upgrade 2 older 12 packs that have plastic wheels and what appears to be a lower quality truck.I was messing around with P2K 33" wheels inserted into the current trucks,but they bound up and would hardly spin.Athearn Genesis ASF 70 ton trucks had a wheel base too wide and the middle/inner wheelsets rubbed the car.Any help would be appreciated.
Thanks
Jim

If the trucks on the ones you want to upgrade rolled freely with the original wheelsets, try reaming out the axle holes in the original truck frames. The best tool I found for that is the Truck Tuner from Micro Mark.

http://www.ares-server.com/Ares/Ares.asp?MerchantID=RET01229&Action=Catalog&Type=Product&ID=82838

Why not email Walthers directly and ask them to sell you new wheel sets. They are very helpful if possible