Not to get too far off point but this is still relevant to the thread, what about high flow mechanical water pump? SR Performance and Edlebrock both make high flow water pumps for the S197 4.6L but, i'm skeptical of their improvement over stock since they don't present any flow comparisons between stock and themselves.

Edlebrocks has a slightly larger bearing diameter and both SR and EB have a larger impeller without the support wheel.

https://www.americanmuscle.com/edelb...E&gclsrc=aw.ds