That engine (50473) is a 1974 50hp Evinrude model, not a 1973.
You don't say which bolts..... there's a lot of different ones. However, if you're speaking of the cylinder head bolts, that would be 18 to 20 foot pounds in the following sequence.
Re-read my reply. I don't know how to word or explain it any simpler. Stand in back of the engine, facing the spark plugs. The numbers I listed correspond to the bolts.