'71 Demon with 360. I have an aluminum rad with electric fans and shroud. I want to take the electric fans and shroud off and replace it with a mechanical fan with a clutch because it gets hot on the highway (not in town). I think the flat shroud covers too much of the radiator.

What size fan should I get? I see a lot of 18" fans with 7 blades, sound about right? Would I be able to find a "stock" shroud for it?

I run a 6 blade 18" flex fan on my van with no shroud. Works great for me! Factory 3 row radiator too. Might just try removing the shroud and just leaving the electric fans first though see if that helps. Good luck!

I'm running the MP thermal clutch fan kit with low drag 5 blade fan. (496 B). It cools great in my application. I understand what is sold now as the low drag fan was a production fan in the late 70's/80's if you want to check a JY. I have a big 7 blade fan from a Cordoba as backup but don't need it. Bouchillon also offers a 6 blade replacement fan.

The JY might be a good place to look for a shroud. Mancini is also offering re-pops and might have what you need.

no fan is going to cure 'hot on the highway' the air being jammed through the radiator from driving at 65mph will be WAY more air than any fan can pull, electric OR mechanical.

sounds more like a water flow problem somewhere. bottom hose getting sucked shut at all? old radiator that's plugged up?

I would think that if it's not overheating in traffic, then highway would be the same though.

if the fans pull enough air at slower speeds, then they ought to be pulling the same amount of air while driving.

maybe not though. could be you're making enough heat at freeway speeds the fans couldn't keep up.

go ahead and give it a shot though, remove the shroud and see what happens.

I have one of those dual electric fans with a shroud & while it's not installed & I don't know that it will be a problem I already plan to modify it & you may want to do the same... I plan to cut 1" x 3" slots in all the flat areas to open up the air flow.. But then I plan to attach rubber flaps to the engine side of the shroud... Now when the electric fans are running at low speeds the flaps will be pulled shut & air will be drawn through the radiator but at higher speed the flaps will open up & allow air the pass at a higher volume than would get past the fan...

BTW I can't believe I typed out the above post, I originally clicked on the thread to post a smartassed comment about how this fan should do the job...

Wild RT you are outta control!!!
YOU should be a Mod!
I never had much luck with the clutch fans, run an 18" stainless flexfan, at least 1/3 into the shroud.
Rule of thumb, after about 35MPH the fan don't do nothing.Air flow from grille takes over.
A smart fellow once told me to think of air as a fluid, one needs to direct it and dam it to where it's wanted.See if there's anywhere you can put in some easy sheetmetal or plastic 'dams' in front of the core to channel and/or block off any air from spilling around the front outside of the core, and force it to got THROUGH the core.
MrG makes a large window 180'harris type thermostat for about 10.00 too.