During the late '70's oil embargo, I converted my 340 FS FB Barracuda to a fuel economy. I rebuilt the engine and used a 318 cam. I put in a 4-core desert cooler brass radiator (at the time, $25! Wow!). I used an electric cooling fan (Flex-a-Lite) and a transmission cooler in line with the radiator cooler. After fine tuning the AVS for economy, I got 22-24 MPG and drove the car to Tuscon in 117°F heat and the car never got above 180°F except pulling grades. Then it got to 195°F or so. Timing was stock as I didn't know about all the tricks to change the advance curve at that time.
Despite the downgrading of the 340, it ran 14.50's at OCIR. Stock it ran 13.50's, so a drop in performance, but still quick.
Now I run the 340 with a MP 280/480 cam and an Engineered Cooling Products radiator with dual electric 10" fans and a Moroso high volume water pump. In the Dener area at 5800', air density is lower, so cooling is more critical as even at the same SCM, there is less mass of air flowing through the radiator which limits heat transfer.
