First off it has a 390 and a t18 I believe and I'm in the market for a new clutch here pretty soon, it hold fine under normal driving but if I give it to much power as im taking off it will spin the clutch for a bit and under high torque like offroading it will spin. I'm looking for a bit stronger pressure plate and was wondering what everyone else was using before I spend too much on a race type clutch. Second thing is the fan clutch is going out, im thinking of using an electric fan to gain a few ponies and maybe get a few more mpg's. I drive it to the desert quite often and was needing to know that cfm range I should look at. The stock fan clutch kept it cool really well and I want to be able to trust that its going to work the way I need it to. I drive 100+ miles to the desert and its never gone above 170 untill recently and i noticed that the fan clutch is leaking. Would 2000-2500 CDMA enough? And should I go with a manual fan on a switch or a thermostat fan? When I had my 5.0 I had problems finding a reliable place to measure engine temp from because most measure temp going into the motor and not anywhere near the head where you need it.

 

Get at least a 2500 CFM fan with Thermostatic switch.... manual switch? only have to forget it once, and you are up doodoo creek . There are quite a few Electric fans with matching shroud that will work, give it an Ebay search! I have a Dual fan with shroud set up, and I also went to a High Volume water pump, and Thermostat set... High volume water pumps require the use of a High volume T-stat, but they also free up Ponies as the water pump is much more efficient. If you have the Old style non clutch style fan, you will see a nice improvement. but if you currently have a fan clutch, the difference won't be quite as noticeable... As far as a clutch, I found a real nice clutch, on Rock Auto, it was not cheap, but it wasn't outrageously priced either.. if you are doing a lot of heavy rock crawling, you might want to step it up, but if it is a daily driver, pushing that heavier pedal can get to be a chore.... The big question is what is the primary use of your truck, and then buy accordingly!

 

If you have been staying comfortably cool with the current fan clutch until it started leaking...replace the fan clutch and add the high volume water pump...check for good flow in the radiator as well..
On the clutch itself...if its spinning a bit now...check for proper adjustment first off...if it is grabbing really high on the pedals travel...clutch is either way out of adjustment or in need of replacement...
I have a friend who had a 64 4WD with a transplanted 390 and a non fan clutch..never once had a cooling issue...and the truck was used hard too for a long time...
I have to do the clutch in my truck...110 clams for the clutch kit...



- cs65

 

I do some pretty nasty wheeling in it when I'm out there lol I also have to pull others out when they get stuck so a strong clutch is in order. The clutch does grab very high on the pedal and any pressure at all will make it slip.

 

Very high pedal/clutch grab point...clutch is done...clutch grab should be 2-3" off of the floor ideally...


- cs65

 

That's what I figured, I know its time to change it just looking at some options. They have a stage 2 clutch on summit for about 350. Other question is should I go for the thermostatic fan clutch or the regular one?

 

Fan clutch from AutoZone doesn't fit, part number 922710. The bolt pattern on the fan blade is wider then the fan clut

 

Clutch* so now I'm struggling to find out what the right one might be, the fomoco numbers one the fan are d6ta-aa and 916413 f76 if that helps.

 

Figured it out, turns out the radiator, fan and fan clutch are for a 460

 

cool...so i would figure you got a stout clutch up front...just gotta get a good one that doesnt leak...

As to the trans clutch...i personally wouldnt pay that much for a clutch kit...unless I was strictly racing...and if you do use the truck uber hard...remember...a chains only as strong as its weakest link...with the miles on it and so on...something in the trans or driveshaft or rear end could fail...and as tough as I know these trucks are...and as much weight Ive had on my tired as heck clutch...a regular HD unit should suffice...
A word about autozone...which i do like...I got a wheel cylinder from them once...66 F100..house brand...looked right and so on...wouldnt fit on the backing plate...spent 2-3 bucks more after lotta cussing and filing on said backing plate...in the vice...and the Bendix cylinder fit in there good as original...
I would get a good name brand clutch...both clutches...LOL...



- cs65

 

Yeah the fan clutch was a severe duty with a lifetime guarentee and the clutch I'm looking at is a centerforce 2 dual friction that's supposed to be 70% better holding power then stock, I didn't think I would have this many options when looking for a clutch lol. Is bigger better as in 11, 11.5 or 12in clutch and should a 12in fit?

 

I still need a little help choosing a clutch, will any clutch with a 1 1/16 10 spline shaft fit? Will a diaphragm type clutch work or does it have to be levertype?

 

Marked: D6TA-AA = Ford part number D8TZ-8600-A (replaced D6TZ-8600-A) .. Fan-Use with Fan Clutch (has 2 5/8" center hole).

1975/76 F100/350 360/390/460 / 1975/79 Econoline 351W/460 / 1977/79 F100/350 351M/400/460 / 1978/79 Bronco 351M/400.
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Now that you know what the applications for the fan are, what radiator does the truck have?

Is it this? D3TZ-8005-G (replaced C8TZ-8005-C) .. Super Cooling Radiator / 26 1/4" wide x 24 11/16" high / 2 5/8" core thickness.

1968/76 F100/350 360/390 (except 1973/76 F350 390's on the 140" wheelbase) / 1973/79 F100/350 460 (except F350's on the 140" wheelbase) / 1977/79 F100/350 351M/400.

If the radiator is 26 1/4" x 19 3/4" with a core thickness of 1 15/16" it's an Xtra Cooling or A/C radiator. There are 6 different types.

Original radiators have a brass plate with an ID engineering number marked on it.

 

Thanks Bill, I know its thicker then 2in.