As long as the Tuner card you are installing has a PCI-Express interface.
PCI is not PCI-E.
But a PCI-E x 1 can fit in a PCI-E x 1, PCI-E x 4, PCI-E x 8, or PCI-E x 16 slot.
Very Very Important... please take my advise... if it Does Not Fit.... Do Not Force It!.
If it does not even line up... do not try it.
Most everything in a PC is built so that only that that is supposed to fit will or can.