I got this flex fan with a batch of parts I bought years ago. Does this type of fan do a good job of cooling?

Not sure how well they cool (I use the MP clutch fan kit), but they're not good for performance: https://allcarvideos.net/2017/05/01/cooling-fan-shoot-out-engine-masters-ep-20-2/

those things make a ton of noise if nothing else.
look real close at where the blades meet the fan center. i have seen the blades crack there, and you DON'T want to be hovering around the engine running when a blade decides to part company !

i installed one on my 345 International truck. I had the van body off chassis only and I was driving to Miami on I-95 in beautiful weather, dry as a bone at around 2:00pm. Oddly I noticed in my mirrors my rear tires were shiny like they were wet.
That made no sense, so I promptly made a side of the road safety stop.
A SS flex blade had broken and severed the rad hose, losing all the coolant. Lucky the engine never got hot, and I wasn't standing by looking at the engine running while parked when the blade failed.
Not sure whatever benefit they might have, they are NOT worth the risks. If your neck was struck, it would be lights out forever.

Those things are not but junk. Never could understand why a guy would spend tons of money on a car then put a cheap prone to failure flex on on it.

Man you must buy junk ones.Have ran one on my old Jeep for years.The one on my 440 now has been on at least 25 years Kid runs one on his built 360 also.they never overheat and as far as noise none.Had lots more trouble with clutch fans than these.Seems most times overheating problems are clutch fans.

They flex great with RPM until they don't. It flexed apart right through the hood of one of my buddies 87 Monte Carlo S.S.with a built small block Chevy.

We used to call those things "choppers".
There's some merit in fan blades flattening out with RPM, and I seem to recall a GM version in the '70s or so.
Plus they're not made from Chinesium, or riveted together by people who are free of liability.
My point is, if you can't run a dis-engaging coupling, at least lose the blade pitch with RPM.
Of course, an electric puller fan can also work with no HP loss.

Have never bought one. Just a observation from what I have seen over the years.

Fans like the one pictured do not cool near as well as a clutch fan (especially if you’re using a HD clutch).

I have built cars where there is not enough room to run a clutch fan. In those instances, I’ll find a factory flex fan. I can usually source then from a Ford who seemed to use them on a lot of 70s passenger cars. The blades have a lot more pitch than the aftermarket units (better low speed cooling). So far I’ve never had one come apart…..which I can’t say about aftermarket units.

Personally the fan pictured would end up in the swap meet pile.

Just my