Well we had some issues with over heating... Think mud got caked over the radiator and the fan didnt help much. Do yo guys run a thermostat in your rigs? Im worried about warping the heads if i overheat too much.

I think i have somewhere in the ballpark of 9" of lift. 6 suspension and 3" body. I am running 38.5x15x16.5 tires. It needs gears badly and some more motor, but i am currently running the IFS with 3.55 gears. Spins the tires in the mud, but doesnt feel like the motor is revving up right, like the secondaries aren't opening when i floor it. I will post some pics of my carb as soon as i get home to see if i am running everything right.

Ill throw up some pics soon and let you guys fill my head with usefull information

 

The pickup in ur signature??


Auto, or manual?


Clutch fan or no? If yes it could be shot.

 

the way my thermo stat is not spring loaded but just a small resistor to slow water down a little, like dave said clutch could be shot on the fan, but the under gearing prolly isnt helping either making your engine work 2-3 times harder

 

I drill a couple 1/8" holes around the flange on my t-stat.


An electric fan (one off a Taurus or Lincoln MKVIII) could help

 

Thermostats are for street trucks.













Oh, wait, I have a restrictor where my t-stat was but run an electric water pump.

 

Guess i should have given some more info... Always forget that part.

I have an 86 F250 5.8L with a C6 all stock except for the headers and exhaust. Yes it still has thefan clutch on it and it spins freely by hand. It does not make any weird noises to make me think that is the culprit.

Would an electric fan get clogged up with mud and stop and fry the motor in it? Thats the only reason i thought to keep the fan and clutch.


And i got good news tonight Dads pick up needs a new motor. I got him a good motor at a good price from an Arazona truck. Superclean and appears rebuilt with all new gaskets on everything except for the oil pan.

Anyways... The motor in his truck now has a good top end. Not stock A top end with my old cast GT40's and crane 1.7RR. I plan on using this on the top end for this truck. That should help with the torque out put, should it not? Will the 600 cfm edlebrock be enough to feed all that??

 

The fan clutch should spin with some resistance with like a catch once per revolution.

An electric fan will be fine in the mud. I wouldnt worry about the motor for one second.

A 600 cfm carb should be fine for a mostly stock 351w.

 

Mostly stock with heads that flow 20% better than e7 truck heads and 1.7 roller rockers?

Won't that be good for like 280hp/400tq? Stocks like 210/330 is it not?

Not trying to be a smarty pants, I just am not sure

 

Your new heads can flow 100000% better than your old ones and it won't make much difference at all if you don't have a cam to make use of that flow at the appropriate lift.

20% more flow does not automatically equate to 20% more power.

A 600cfm carb is good for your build. Swap your cam, intake and maybe some headers and you possible could step up to a 750 but its doubtful you'll make much use of it unless you spin it to the sky.

I'll post the cfm formula for engines in the morning.

 

<table class="wikitable"><tbody><tr><td>351 CID Windsor V8</td> <td>1983–85</td> <td>150 hp (110 kW)</td> <td>280 lb·ft (380 N·m)</td> <td>2bbl</td> </tr> <tr> <td>351 CID HO Windsor V8</td> <td>1984–86</td> <td>210 hp (160 kW)</td> <td>305 lb·ft (414 N·m)</td> <td>4bbl</td></tr></tbody></table>

He's got dem headers already

 

So do you think i am wasting my time with the heads, rocker arms and an aluminum intake? I already have LT headers on the motor. That good for a slight bump in power?

 

Do you hear the fan run when you first start the pickup?




Also, good aftermarket heads, a big cam, high rise intake aand a 750 carb can net 400 hp.idk if gt 40s will get u there tho

 

I do not hear it when I first start the truck. N

 

I do not hear it when I first start the truck. Nor do I hear it lock up at any given time. How does it know when to lock/unlock?

 

Heres the cfm formula to determine the maximum amount of air your engine can draw under the most ideal circumstances.


Engine Size (CI) x Max RPM x Volumetric Efficiency/ 3456 = CFM

351 x 6000 x .80 /3456 = 487.5cfm


VE:
.70 - stock engine
.80 - mildly modified engine
.85 - modified engine
.90-1.1 - full race


Given that most holleys and edelbricks flow around 50cfm less than their advertised cfm, I still say a 600cfm carb is all you need. You could bolt a 1400cfm carb on there and not see any added benefit at the upper rpms because your engine cant make use of the extra cfm coming in. Too large of a carb will drastically hurt your bottom end performance also. I was also a little generous in the max rpm department...5500 rpm may be more like it.