Langen and Rgtrough, thanks for your suggestions. I finally found the Zip accessory at Southern:

http://www.southernrods.com/categori...duct-1845.html

Maybe Parr doesn't stock them anymore. I am still mulling over the cost since on another thread C9X shows he runs a 455 Buick with a low flex fan in Arizona! I think I will change to a 160 degree thermostat along with a max-flow low pump. Sadly I usually end up trying three or four things in my expensive "development program". I used to wonder where all the stuff comes from for swap meets, but now I have a better understanding of all the stuff that folks "try" along the way.

Don Shillady
Retired Scientist/teen rodder