1974 century resorter with a 302 mercruiser.The tag says 225R, 225 being the hp .The R being right hand or reverse rotation or are they the same.idk. Ihave found info that says stnd rotation is 15426378 but if it has a 351 cam it could be 13726548.Reverse rotation should be 18736245 or a different 18#^& something I cant remember.below the carb is( firing order) stamped in block but no firing order is stamped.Would there be another place where it would be stamped?