While I'm in there replacing the harmonic balancer, I wanted to add an electric fan, inside the shroud, and eliminate the fan and clutch to free up a few extra horses.
The fan is a 16" 2200 cfm model, but I will have to mount it offset a little from the surface of the rear side of the radiator, due to the oil cooler lines. Anybody see any issues that I am overlooking with this plan? The truck does NOT have A/C condensor in front of the radiator. Also, I run a 180* T'stat, what temperature shoud I set the fan to turn on at? Just above, or below 180*? Your thoughts are appreciated.

I don't meant to high-jack your thread yachtcare but i was thinking of doing the same thing along with trying to find some light-weight pulleys like they sell for the 350 gassers so I am in the same boat as you. I will try and find some info for you. i just hope someone else can help you too.

Newman......Not sure if any of it is interchangeable, but you might want to look at some of the lightweight stuff available for big block gassers. Maybe the pulleys are interchangeable? I'm also researching the use of an electric water pump conversion. If I can do that, the lightweight stuff would be a (almost) moot point, as all that would be running is the alternator and PS pump. I have two group 72 batteries installed, so the fan and water pump with relays would be hardly any drain at all.

When I first swapped a 6.2 into a 1970 Blazer back in 1985, I tried a dual electric fan set up. It was a disappointment and waste of money. The electrics couldn't keep up. Invest in a good replacement fan clutch, when the engine is cool they draw very little HP, when the engine is hot, they have the ability to cool the engine. Stainless flex fans also work, but they cost about 1 mpg over a clutch fan with no improvement in cooling.;)

I installed an electric fan, but it didn't do any good for me so I removed it. I don't think you will get enough air flow thru the radiator when you remove the engine fan, even if you put four electrical fans in front of your radiator. Your alternator takes a lot of horsepower to turn it, especially at full output, so nothing is free.

My experience with electric fans is the same. I found that if the shroud(s) completely cover the radiator, the electric fans are fairly efficient. If the shrouding isn't good, tight and completely covering the core, you're better off with a good fan/fan clutch setup. So often I see electric fans installed without thought to the shroud and guys wonder why it doesn't work or help the heat situation.

My best experience is on my Firebird bracket racer. I have a wide radiator with the dual electric fans and electric water pump. The only advantage is quick cooling between rounds. I run the fans and water pump a few times with the engine off and the coolant temps are down and ready to go again. The whole process takes just a few minutes. Sometimes this is critical. On my street vehicles, the ol' fan clutch and big fan seems to do the trick.

OK, you guys have convinced me to get a new fan clutch for use with the stock fan. Any suggestions on an upgrade? I started a little shopping online and found a standard clutch, and a heavy (severe) duty clutch. Looks like about a $30.00 difference. Since I expect to do more towing in the future, I'm leaning toward the severe duty clutch. But is it really necessary, or just some sales hype?

Spend a little more and get one of Kennedy's custom calibrated fan clutches. His clutches kick in at a lower temp and will save your engine. Most 6.2 head gasket failures are related to overheating the engine.;)

I ran my 6.2 in my K5 with no fan at all for 2 years. However, I did cut the few inches of core support out that cover the extra width of the diesel radiator core. I would deffinately not suggest it for towing, but at speed i never had a problem, at some long traffic lights I saw 200 a couple of times.

I have never had a problem cooling with elctric. i have run them on big block gassers, and small blocks alike in various states of high performance. On my dually 454 I put 4 small to medium size fans, 2 pullers inside set diagnal, and 2 pushers mounted on the a/c condenser set at the opposite from the inside 2 in theory I had nearly covered the radiator with fans, I set the t-stats on the inner 2 to run at around 180 and the outer 2 to kick on at around 200. I would manually turn on the outer 2 when ever I was running the a/c as it seemed to work better. I did see quite alot of draw as I only had one battery. So to insure as long a life as I expect from the battery, I would shut off all draw possible before shut down and run at a high idle a bit. I planned on running a big pusher and a big puller on my '84 6.2 GMC. Brent

Hogdogs, I've seen fans in vehicles with gas engines wired from the ignition switch to toggle switch to fan and they suffered engine run-on after the ignition switch was turned off. Caused by the fan motor feeding back into the circuit that powers the ignition (distributor). By putting a diode inline with the wire from the ignition switch to the fan toggle switch, the circuit is broken when you turn off the engine and it stops as it's supposed to.

My daughters '76 Nova had the electric fan wired this way when she got it and the first time she used the fan on a warm day, the car wouldn't shut off! I wired in the diode and fixed it.

Being both a decent "shadetree" REDNECK, and an electrician, I always wired off a busbar direct off the battery. So I never had the problem. A buddy did have that problem. We "fixed" it by putting one of my spare switches inline to kill power at any temp to the fans before engine shutdown. It did require a label on the dash stating "flip switch, stupid" to prevent a beer or other distraction from causing a severe overheat situation. I won't have that problem on my diesel, will I:eek:):h I will focus on my exhaust and fuel pump timing first. Thanks for the tip. it may help someone driving a gasser. Brent