Will a 27" fan fir? I thought I remembered measuring the stock radiator at about 20" x 20". I guess I could be mistaken.

hmm.. thats weird .. maybe im the one that is wrong .. coz i measured mine at 29" .. i forgot the height .. soprry if i gave a wrong info ..

I'll double check mine, too. Now I'm curious!

Finally got another measurement on the radiator. It's roughly 21.5" by 21".

Any physicist will tell you that there is no free lunch.
Driving an electric fan, if it is moving the same amount of air will require the same amount of power from the engine but it will be through drag on the alternator rather than direct drag via a belt.
On the other hand, driving an electric fan pulls engine power at different times than does a fan clutch due to the battery acting as an electrical shock absorber.
TIM

Agree. But a more efficient fan will opperate less. So it would ( could) worth it, Batery does act as a BIG sock absorber reloading. Byt thin the fact that the fan is rotating even on the freeway were it is not needed, maybe not engaged but still dragged.

The added drag of the alternator would be a fraction of what it takes to drive the clutch fan. Also, as you stated, timing is the whole point. In the summer, every time you stop the clutch fan engages causing lost power (and lots of noise) when you need power the most-for acceleration. Not that every takeoff should be at full throttle, but any added drag while pulling away from a redlight or stop sign will affect the way you drive. Most of us try to compensate for the lost power by increasing throttle resulting in poor fuel efficiency in addition to the lost power that is already being experienced. The clutch fan even creates drag when it is not engaged. If you don't believe me, try this: start your engine, open the hood, now try to stop the fan. If you use your bare hand, you'll probably lose a finger. If you use some other object, The fan will probably shatter on impact. The drag that drives the fan, even when it is disengaged, affects your engine all the time as long as your engine runs. It's much less than the drag created when the clutch is engaged, but it's still there.

its a good thing you specified what happens when one sticks a finger in a radiator fan. . .i can envision a future post: 'rundodge owes me a hand!' lmao

Good point. I hope noone took that literally!

i hope so too ... oh yeah .. i measured mine too and it is 21" ... so it seems like the flex-a-lite 20" 'S' bladed electric fan will mount on the stock fan shroud mount .. well .. thats what seems atleast .. but i guess a little creativity will fix if there is any problems ..