The CN Fowlers have been photographed on Arch-bar trucks, "Bettendorf" style, as well as "Simplex Bolster" trucks. Life-Like was offering Simplex Bolster trucks, but a recent attempt by my local hobby shop to order some from Walthers meet with failure.
I believe that the Simplex truck was a Life-Like Canada product and thus is now a Trueline Trains product and thus is not available from Walthers under the P2K name.