If the 53 has it's original engine it would be the last year for the splash 235. Although it is a good engine it is not what most people use. If it is a good runner you could run the rest of it's life out of it and watch for a full pressure 235.
If it is the original splash 235 it will have the kidney been shaped cover, held on with three screws, seen just below where the exhaust dumps in
this picture.
