Do you need to pass emissions, are you using the EGR port? As long as you are not using the end seals (cork or rubber) and are using a bead of Permatex/RTV you can use the gaskets from a 351W.
In the STANDARD MR Gasket they list a
#210 351W 1969-74, 1.25''x 2.11'', 1/16'' Thick they should work, however may not have the emissions ports.
ULTRA SEAL
5834 302 1977-95, 351W 1975-83 (except 302 Boss)
Note: These gaskets are made of a material that is less compressible with an anti-stick graphite coating and no silicone beading.
5835 1986-95 5.0L EFI (THIS MAY BE A STOCK PORT SIZE)