Don't listen to anyone telling you they have left hand threads. They have normal "right-tight, left-loose" threads.

 

Except the older ones with V-Belts.

 

The V-belt clutches were held on by the water pump bolts.

 

I have a 1981 sitting outside that's not and I also have a 1983 that's not.. They are plain jane pickups with no air. .. If you want to go back to the 60's and talk about them with V-Belts, then I guess you are correct BUT my statement was about the 4.9s with threaded fan clutches. .. . Heaven forbid someone making a statement that can help someone...

 

You are correct Lonzo.. I bought a new water pump from AutoZone instead of a rebuilt and the casting was thicker..This was on a 1990 model. I compared it to a 1995 model I had laying around and the new one was thicker than it also. This was 4 days ago.
I have 4 running pickups with the 300-6. and I have 5, 300-6 engines sitting on the floor waiting... I like them and my son likes them so we buy all that we can and save them for a rainy day..

 

All (two) the v-belt engines I've worked on beyond pulling parts in the junkyard has been 70s industrial stuff. I assumed that the water pump didn't change until they went to serpentine belts.