About 25 years ago I purchased a vehicle and was told the engine was a 400 from a 1968 Olds 442, shortly after I got it I needed to replace the water pump. The first replacement I got looked the same but it was about an inch too short, the pulleys wouldn't line up with the rest. I eventually found the right one and all was good. Fast forward 25 years and I got this engine back, needs a water pump again. Same story, new one is too short again. Is there something I'm missing here? Does anyone know anything about this? It's possible I was misinformed about the year/size of engine. Any input would be appreciated.