Now that I'm at the lot with all the wonderful Isuzu resources...

Front Speed Sensor is Key 357(A) in the diagram previously provided. The up-to-date part number for the component is 8-97251-686-0. The Rear Speed Sensor is Key 357(B) in the diagram previously provided. The up-to-date part number for the component is 8-97251-685-0.

I never would have been able to figure out which part was front/rear without a VehiCROSS electrical troubleshooting manual.

Isuzu's suggested retail price of the front speed sensor is $314.17, with a suggested wholesale price of $267.04. If this is something you're planning to do yourself I can have the part drop shipped to you for just over $220.

Sorry it took so long... don't have the resources at home that I do here at the dealership.