if he's smart, he'll find that a '53-'54 235 looks just like a 216 except there full preassure, '51-52's look just like 216's but they are not full preassure just like 216's. about the only boat I can think of is like a late 40's chris craft or somthing, even then, alot of those old boats get repowered with newer engines for reliability. a 216 will cost more to rebuild than a 350 would be to fit in the car, and being a babbit bearing engine, bought cheaply, it should be at least opened up and checked out, JMO