Winterizing an '87 2450 is a piece of cake. Used to own the same boat. Single small block I/O, no hot water. Pump the head, drain the water tank (each only 13gals) add some pink stuff to each and you are done with the ship's systems. For the engine, drain block, drain mainfolds and you are good. We used to also remove the thermostat housing and fill block with anti-freeze, but you can just drain if you want to continue to use the boat. When you are ready to put her down for the winter, change engine oil and I/O lube.