Is 73 the only year for the 350? The book i have lists 74s at 260 or 6 cyl.

 

Not even close. According to Setting the Pace, the 350 V-8 was available in every year of the Omega from 1973 through 1979. Only V-6's after that to the end of the Omega in 1984.

 

Unfortunately, it wasn't always an OLDSMOBILE 350...

For example, the available engines in the 1979 Omega were the Buick V6, the Chevy 305, or the Chevy 350.

Actually, the base engine in the FWD Omega was the Iron Duke four cylinder. The V6 was optional.

To the OP's original question, however, the 1974 Omega offered the 250 I6, an Olds 350 2bbl, or an Olds 350 4bbl.