No. 32-bit PCI cards require a 32-bit PCI slot... they won't even fit into a 64-bit 66MHz slot, since the slots are keyed differently. More precisely, a 32-bit slot will accept 32-bit cards operating at 33 or 66 MHz. A 64-bit 66MHz slot will accept 64-bit cards operating at 33 or 66 MHz. A 64-bit 33MHz slot will accept 64-bit or 32-bit cards operating at 33MHz.
There may be some 64-bit cards that are dual-keyed so that they can also operate in a 32-bit slot, however.