I used the one spec'd for cop car apps. I think its a max cooling package part. the main visual diff is the shaft dia. 5/8" vs 1/2". It always kept my 340 cool , stop and go woodward cruise or on the highway @ 70 , 80 or more.

Part #4728533. don't know if it's still ava.

I'm using a Milidon hv pump on my 416 , it does ok but the temp seems to creep at highway speeds.