I worked on an outboard speedboat once that was powered by a 318 & it was reverse rotation! iirc the firing order was 2-1-8-4-3-6-5-7. starter bolted in the bell from the front. EDIT I read something once about there are precautions needed if its in salt water (cuz it cools with that/salt corrosive). if it runs good (do std eng/drivetrain checks & the wife is happy I'd say you are set. I would continue to search for some boaters who can better advise you on the ins and outs