|Mid-way through the production run for the 2001 model year, Ford changed the design of the water pump on the 4.6L engine. The older style pump produced from 1996 to mid 2001 had a longer shaft. In January of 2001, the design of the pump was changed to a shorter shaft. This necessitated a change in the design of the pump pulley.
You should visually identify which pulley/pump you have before ordering underdrive pulleys.
The old water pump pulley had a convex or "bowed-out" face, the new design has a concave or pressed in face. There is no exact changeover date for the pump and pulley. It is important to visually inspect your car to see which design you have. Supposedly the changeover occurred in January of 2001, but there are cars with identical January build dates and different water pumps and pulleys.
* Please be advised that this information is for suggestion only and is based on prior experience. We at CJ Pony Parts can not be held responsible or liable for any mistakes or injuries connected with the topics covered.