I got a clutch fan (stated as having a good clutch), 5 balde, off e-bay for 10.00. It was on a 73 Electra 455, fully loaded. On my 73 Century GS350 w/a 455 I have a stock 4 blade fan that is not clutched. Should this make a temperature difference when in traffic? Also will a 7 blade clutch fan off of a buick 350 bolt right up to the 455? Thanx for any help.
I went from a 7 blade flex fan to a 5 blade fan with a non thermostatic clutch on my 72. Temps went from 190 while driving , 220 when stopped at a light to 160 while driving and it might hit 180 when at a lengthy stop light. I'd say it will make a big difference over a factory 4 blade and will free up horsepower to boot.
I agree with Mike. The thermostatic coil type clutch isn't as desireable as the non thermostatic, viscous type, performance wise. As for the 350 and 455 fans interchanging...I would suggest caution. Although the two engines share similar dimensions physically, there is a spacer involved for the fixed fan, and I wouldn't bet that the two fans were designed to space themselves properly on different water pumps/timing covers. You'd have to measure that one out.
7 blade 18" clutch fan is the same for 350 and 455, I believe. The fan clutch acts as a spacer. There may be a difference in the hole in the middle of the fan, one is 2" and the other is 2 5/8". I use the NAPA 271301. It is a much heavier duty clutch than the Stock Buick. Moves alot of air. Bolts right up to the 7 blade fan providing you have the 2 5/8" hole.
I purchased a 19in. 6blade replacement from Autozone(year one has them too-as I'm sure does everone elese), and a heavy duty thermostatic clutch listed for a 70 skylark(with a 455). On a 94Deg. day with AC I run 189 all day.
