Probably be better for you to start a new thread. This ones nearly three years old!

 

Thanks I am new to this stuff ...got NO idea how to start a new thread ...I'd be glad to learn thanks, Dave

 

On the main forum page, there is a FORUM TOOLS that you have to click on and that'll take you to MAKE NEW THREAD. From there give it a title and the rest of your post and thats that

 

Good threads never die! LOL :)

You sure about that 3.55 rear axle ratio? :/

Anyway I've got a parts truck just like yours (except for the rear axle ratio)
and a '91 Bronco with those tires and axle ratio and it has the 2wd ZF from
the F250 in it.

Ok, so what I did was advance the cam timing 4 degrees and gave me a
good 1+1/2 MPG and a more usable power band both at the same time.

Cloyes Gear 9-1138 ~$50

Do that first it's cheap to do and change out your thermostat to a 195F
Robert Shaw type that looks like this...

http://www.panix.com/~alvinj/file12/RobertShaw.jpeg
http://www.panix.com/~alvinj/file12/RobertShaw.jpg

Here's part of the reason why but more important for you is the EEC is
running rich for warm up if the temperature isn't up where the EEC thinks
it should be.
http://www.panix.com/~alvinj/file12/CylinderWear.png

309 - EMP Stewart High Performance Thermostats ~$20
(all them look to be made by one outfit so don't fall for the higher prices)

Alvin in AZ

 

Thanks Alvin
Yes it is a 3:55 non-posi for sure. I was looking to change ratio to 3:73 fo a better power band we got some hills here and I do pull a trailer now and then. You mentioned the t-stat it is 180 deg.fail safe unit (fails open not closed)I just read an article about that and was on my todo list. And thanks for the timing idea ... that just joined that list too. What was the Cloyes Item ??? getting the O2 sensor checked in the am too.already have a SS 2 chamber muffler on it now...about 2 yrs old. It is a great old truck I put 12K on it in 2011 driving around the USA ...It's ugly but works good ... kinda like the owner !!!

 

Thanks for confirming that 3.55 business. :)
And I'm going with a 3.73 in my light weight Bronco that I don't tow with.
It's a very small change and only worth it to -me- for a very odd reason.
I'll be adding an Eaton True-Trac at the same time to an open 8.8" I have
that's got no more than 75k miles on it and put that under my Bronco. :)

IMO, it won't be worth it to you in your F250. I'd suggest a 4.10 for your
heavier truck that might actually do some work. LOL :)

Here's what started out as just notes to myself and grew into something
a few guys have found useful...
http://www.panix.com/~alvinj/file12/600rpm

Do not install a "fail safe" thermostat danggit! :)
They are crap. No kidding.

The Robert Shaw type is failsafe by design, but they're not to be confused
with those advertised as "fail safe". And don't install anything less than a
195F either because it'll cost you money in lost fuel mileage.

Google is your friend... ;)
Cloyes Gear 9-1138 - Cloyes True Roller Timing Sets - SummitRacing.com

Got an oil burner of an engine and/or over 60k miles on the O2 sensor?
If so... it's shot! :)
Just replace it with one from Rockauto.com and save your money. ;)

Alvin in AZ

 

I am impressed at the detail to which your "chart" goes into for tire size/gear ratio/ mph and all that. It helped me to decide that the 3:73 gearing would work best for me the way I use my truck. Trac-lock will be an item for the future improvement.... when funds are better. I got a Robert Shaw type t-stat at AutoZone sold by Mr Gasket I will be water testing it soon just to make sure. Ran a scan on the truck while there... it showed no codes =)
The t-stat and timing will get done ASAP ... The weather is kicking up ... cold and "tie-yer-***-to-the-truck" windy (garage area has no heat) and some kinda holiday thing (other than NFL) on Sunday The O2 sensor, mine only has 1,for the 8800 gvwr (soon as I look for it) You are right good old threads never die they hibernate ... I hope your info and my project will help others too. I will keep you updated as soon as I get things done ... MERRY CHRISTMAS to all, and to all a good night !!!

 

Well I got the t-stat in and I'm not sure it is working properly ... the motor heats up and produces plenty of interior heat yet it never opens in the radiator with a large flow of hot coolant. My temp gauge/sender (where ever it is) has been suspect for a while. Dash gauge never goes very far up the scale (sender?) There NO outward signs or smells of over heating ... So I'll roll with it for now. I, misread you comment about the Cloyes set ...but it will be included in the rebuild later. I did advance the distributor to 14deg, BTDC I will check the driveability next week on a trip to Vegas (65mi. over a 5700+ ft hill) After Jan 1 I will be looking for some emission equip. headers short tube style with 1 5/8" tubes and 2 1/2" outlet ... nothing fancy ...used if I can ... My Santa list....new or used shorty headers, 3:73 gears, some type of locker rear end ... To all who read this, MARRY CHRISTMAS or what ever you believe ... KEEP OUR COUNTRY FREE !!!!

 

Happy New Year to all, I took my trip to Ca. (Lake Elsinore aprox 240 mi. one way) the beast preformed nicely .. better power in 5th ...pulled better not as much shifting on grades. Much nicer interior heat ...the heat gauge even moved. MPG was a little better going south and a good bit better on the return trip, I think I'll finish the 6 L tune up. going to find a fresh air intake hose (air box to grill) from a 94 f250 looks to be bigger than mine... new cold/fresh air intake ..more airflow, then cap,rotor and coil oh yes and plugs. All the advice worked well so far ...BIG THANKS !!!!

 

Hello there names Ben. I just want to get a few extra ideas on what to do with my 1996 Ford F 250. It has the 351 Cleveland in it with and auto- trans. and it is four wheel drive. I'd like to get some more fuel mileage and power out of it, but just not quite sure on how with these motors. This one is the first 351 that I have had. I've had the straight six and 6.0s before just never this one. So the more information about them and what I can do to get what I want out of it will be very helpful. I live on the Oregon coast for now and go up in the woods for work a lot so those I'm sure can be some big factors. Again whatever information I can get from you guys will be very helpful.

 

Hello Ben.

The last post in this thread was in 2012. You are better off posting your own thread. But this thread has good information on what needs to be done with recommended cams and different set ups that apply to your engine. Just read through the thread and/or start your own.

FYI, you more than likely have the 351w as the Cleveland was never offered in trucks. And not since the 70s I believe.

 

Thank you very much for replying. Thank you for pointing that out to me too.