Thanks

I hope this is what you need.

In the 1958 Ford Truck Shop Manual page 2-83 under Water Pump-MD and HD V-8 Engines,

 Assembly:

 in Fig.17-Hub Installation-Typical

it gives the following:

4.15-272,292 MD AND HD V-8 ENGINE. 

Right beneath that it says:

4.72-272 (ECW) MD V-8 ENGINE  

Hope that helps

Mike