AHHH! I remember being 16, when headers are important because they are big & noisy. There are header people and cast-iron manifold people. There are plenty of discussions all over these forums. The best compromise is:

https://www.ford-trucks.com/user_gal...143154&width=0

The only problem is that these are so rare that a pair would cost more than most of our trucks are worth. Still, it solves a lot of the problems with headers and restrictive manifolds. When you do buy headers, consider th e Tri-Y's as they are designed for torque. (Note thcast-iron headers in the pic are Tri-Y.)

BlueOvalBud: Just keep your foot out of it on a grade & gear down. So long as you are patient, you will have no problem. Do not worry about short periods of full throttle, such as freeway ramps or short grades. (If you want to pretend you are a big truck, get an exhaust pyrometer and set a limit on how hot you will let it get before you back off and down-shift.)

You are way ahead of us "old-timers". You have these forums as resource to learn from and can avoid making every mistake yourself. Keep asking questions, being careful to give people all the background info up front. Then read through it all and form your own ideas from all the information. Another thing is to learn to search the forums as most questions get answered over and over again. (Sometimes the answers are even agree!) Finally, there are articles which try to collect the most-needed info all into one place. I hope to contribute to these as I realize that my long-winded answers are a bit much for the forums.

 

Cast iron headers can be had for $500, don't know if it's a pair or each, ouch!

 

I have installed dual exhaust on a 352, a muffler shop eliminated the crossover (a frequent cause of #8 exhaust valve failure) and then a new pipe was fabricated for the left side of the F250, two long glasspacks were added for a free flow and nice sound. The cam was an elderbrock mid-range for low end torque. I towed a 6000# trailer in the Sierra, with 10MPG. The engine had been bored, and a 390 crank installed with a four barrel carb and sodium filled valves, nice rig.

 

66f25red:

Welcome to the forums.

I agree; your's is a nice rig. It is just what I would recommend for towing. The only down-side I have found with a 390 is that it still gets only 12 mpg when not hauling, but you can't have everything.

Are your sodium-cooled exhaust valves in 390 heads?

 

Can you please explain this above statement in detail with facts and proof of this above statement?

 

The exhaust valve in # 8 cylinder, is effected by residual heat in the original exhaust system flow. The crossover from the front of the engine, to the right side allows the temperature of the #8 exhaust valve to stay very hot since the exhaust gasses must exit forward across the front of the engine and out the passanger side this temperature rise will eventually warp the valve and cause it to fail to seal. Of course if you never actually use the F250 to pull a load, it may not fail in the time you have the truck.


By having the left side exhaust (drivers side) removed out the rear of the manifold, all the valves on that side benefit and stay below critical temperature.

I simply had the exhaust system modified to allow a true dual exhaust and the left side of the engine to breathe better, a full dual exhaust has two pipes from the engine, (one left and one right) so the flow is better. This is what is set of headers does among other things. Many "dual" systems only add a muffler with two outlets that appear to be dual exhaust.

 

The original 352 heads were used with sodium filled exhaust valves and new bronze valve guides. The work was done by a speed shop in Reno NV, they specialized in drag boats actually, doing engines like mine for towing as requested.

 

I have never encountered a said above reply about burnt #8 valve the last 37 years beating and towing hard with Fe motors with over a million miles under the right throttle foot. You speak something I have never encountered.
First off headers are installed vs those POS log manifolds with 4 barrel intakes and a proper tune. I pull aluminum pontoon boats every year 300 plus miles one way 4 to 6 times a year, haven't "burnt #8 exhaust valve" yet.
What gives, should I want a build that causes a burnt #8 valve?
I don't think so! Stainless valves and hard seats only here.

 

beemer, The number 8 valve problem was long term thing, many miles of use. I also towed with the 352 prior to the rebuild without a problem.

However after several years working with the product as a technical consultant for Ford Motor Company, teaching a few classes, and then working for Ford Dealers in the Service end of things, I did get some knowledge of the long term effects of the OEM exhaust heat around #8. I chose to do the modifications at rebuild, to eliminate the tendency to burn the valve, since I was going to be towing a 5000 pound + trailer around California, with a lot of climbing to be done.

We each do what works for us, now at 64 I drive a class B Chevy motor home arond the State with my wife. If I had the space I would acquire an older F250 with a 390 and build it also.

Good luck with your setup.