The OEM Stock fans work just fine with OEM cooling systems and engines.

To help answer to often asked question about CFM ratings. The stock electric fan is less than 1000 CFM.. since the stock engine made less than 300 HP, the stock dual fan setup around 1500.

When you begin making substantial power over stock then you need to improve the cooling system.

Case in point I had a 383 SBC that made 465 HP.. the solution was a BeCool radiator and dual OEM fans which I wired in series to a 180 degree coolant switch... this proved acceptable, the car never ran hotter 180 degrees.

Fast forward 12 years and I now have a 421 SBC which makes over 600 HP . The BeCool radiator is rated to handle up to 1000 HP however the dual OEM fans cannot provide enough CFM... operating temp jumped to 200-220 in stop and go summer use. I have a Derale twin puller fan w/ shroud assembly coming which is rated at 4000 CFM, that will help cooling substantially over the stock fans.

So using a simple HP to fan CFM chart on BE Cool's website you can see what you need to support a modestly powered engine. http://becool.com/coolsearch

Remember the key to successful cooling system is the radiator and fans must be sized for the applicable HP level.

Be Cool is one source but there is also Derale, Griffen, etc. there is not one magical part, it's a system.

My advise if it is a relatively stock car; keep the stock system in proper condition. make sure the fan(s) work, flush the radiator, also the lower air dam is important for proper air flow ! repair / replace missing or damaged parts.

If the car is making over 300 real world HP the stock system should be replaced. Keep the junk yard parts in the junk yard ! Unless you find a 4th gen f-body, Viper, or Vette, junk yard parts are not high-performance.

 

i must have been doing something wrong in my 71 Nova (i know, not a 3rd gen F body, but the principles are the same) when i was keeping the 400 or so HP 355 in it cool with a crusty old 2 core copper/brass radiator for a Nova with an inline 6 and an electric fan from a 4 cylinder Chevy Celebrity.. it always stayed right at the 180 degree t-stat temp except for the hot days when i'd jump on the interstate and hold it at 3800rpm for an hour- then the temp would climb up near 200.
i'm not saying that the expen$ive aftermarket stuff doesn't work- i'm just saying that the oem stuff can work just fine with a little thought.

 

The principles are not the same. You are comparing apples to oranges; an X body has a grille.. a very large grille in fact, which help move alot of air.

A 3rd gen F-body has no grille area... they are bottom feeders drawing air from the roadway via the air dam and using puller fans(s) to move the air thru radiator. lose a fan or damage the air dam means disaster.

400 or so HP 355 SBC is just that, a guess.. unless you have 1/4 miles times or a dynosheet to back it up the claimed HP. odds are more likely your combo worked because you did not sit in stop and go traffic and the large grille made up the difference, not to mention you probably were not making the kind of HP you thought you were.

 

I beleave that adding a large oil cooler would necessitate the use of more air flow especially in my situation.My aftermarket trans./engine oil cooler measured 12.5" x 17" and I needed to put it somewhere so I choose to use the stock puller fan placing it over the Derale combination cooler(trans. fluid running at all times and engine oil running at 180*using a temp. controlled sandwich adapter)dead center of the radiator as a back-up fan. I mounted a 16" pusher fan dead center in front of the radiator that is activated with the key on..I salvaged it from the wrecking yard so I'm not sure how much its pushing but it is a monster.I can feel it very well on the other side.Thats how I fixed my air flow problem and do not see any reason why it would not work with higher HP cars especially with the trans. fluid staying cooler with a consistent fan and the stock fan turning on at stock temps if it gets that high.
I do understand that some of our Third.Gens. do not have this advantage,but I have no problem getting air to the front of my radiator.

 

Derale Dual fan assembly went in and works great and looks stock !

The factory gage never went past 240 but I am using the wrong sending unit. with a temperture gun I did get the following readings to set my mind at ease and prove the factory gage is VERY inaccurate until I replace the sending unit.

Car idling in driveway after 1 hour of stop and go driving on 95 degree day

Radiator outlet side 120

Radiator core at fan probe 134 (inlet side)

Sending unit at intake manifold near t-stat 156

head temp 164

block temp 164


This temperature gun is awesome

 

to simply answer the title///when the car gets to hot? O.o