New to the site
The truck is a 1984-85(title says one thing, manf sticker in door frame says the other
But it is for a fact a 6.9l diesel ford f250 2wd with a C6 trans, and loves to cruise slow-
Like 55 to 65 without the engine screeming. The rear end is pretty tall, I am thinking of putting in a different rear end ratio to drop some rpm's for highway driving(which is about 60% of its use, about 5% towing 5000lbs or less, the rest town driving)

Any input from you guys would be great, love the site. Been needing to get on here for awhile, been kind of busy restoring a 1949 3/4 chev pickup that belonged to my cousin(he was born on the chevy side of the family.)

 

never mind figured out the search thing, I am good!

 

Welcome to the site!
3:08 or so would be a good gear ratio for your uses.

I'm sslloowwllyy restoring a '70 GMC ext. cab 3/4 ton 4wd. that belonged to MY cousin.

 

Remember back in the 80's the new models came out in September.

So an August 84 build date could easily be an 85 truck.

Try this link, enter your VIN number in the box.

https://www.ford-trucks.com/vin-decoder/index.php

It should tell you what the truck was when it left the factory.

 

Depends on how fast you want to cruise and if the truck is 2wd. If you want to cruise at 70 MPH for that 60% of your driving and the truck is 2wd, than put 3.08s in and don't look back. The 3.08s will do nothing for around town driving though. It'll be a little slower off the line with 5000lbs behind you, but it will pull just as well once you get the revs up at the end of 1st gear.

 

sorry to ask but will the 3.08 go in the dana rear axle?

 

Something else I will throw out.
Truck has new glow plugs, put those in myself, Start a little rough sometimes, acts like it wants to die, I think it is bad vacuum tubing(it is all original and dried up, as well as possible air getting into the system at the fuel/water separator.
There is a slight weep of oil in the area of the heater hose connection on the side of the engine, Some of the injector lines are rusty, the plastic injector caps with the hoses need replacment and the little orings are kind of leaky.

So my thoughts are to get the kit that replaces the fuel circulation lines and plastic caps with orings, maybe pull the heads to make sure they are not warped/cracked,
and put fresh gaskets in there, while checking over the valves(even thought of new exhaust valves(it has 158,000 miles on it)
Maybe replace the fuel pump and the sending until in the rear fuel tank is acting up.

I thought about in this order-
getting the heads off and checked out, reinstall with fresh gaskets
New pump and water separator
New intake manifold gasket
New fuel circulation hosing with new plastic caps and orings
Get the ac bled down, vacuumed tested, and recharged
Then repaint with some other stuff, might not be the right forum, but I want diesel people to see the engine and mechanical side

all this along with a trans service at the local certified transmission and the faster rear end.

Does this sound reasoable for a truck of this age?

I love the truck(It was my Grandfather's)
Still smells like old John deere tractors inside(his hobby)
and the interior is in great shape.

 

If you have 3:54 gears already the 3:08s should be able to be installed.
Sounds like you have a good plan to me.
The guys on here would definitely be interested in the repaint etc. too.

 

What kind of dana are we talking here? 60 or 70?

I have the ford sterling rear diffy on mine.

 

Head gaskets, valley pan (intake gasket) and fuel return lines would all be done at the same time.
All of that has to come off to remove the heads.

300 K is not out of the question on a 6.9 before you need to be worried about valves and such though.

Head gasket, now that might need replacing a bit earlier, say 200 K or so.

 

I am 98 percent sure that it is a Dana 60 with a gear ratio over 4 in it. quite slow in the take off, but will crawl up a steep incline in D at idle.
The paint sounds like a good idea because it has the stanard cancer on the lower extended cab panels, and the rear end of the bed quarter panels.
Probably a new tailgate(new to the truck)
and a line x bed liner(if I am going to do it right)
But I am really getting motviated to get this going.
Thanks for the input. I want to see if there is any noticeable difference after replacing the cdr valve and the vacuum lines.
Sam

 

If its a dana 60, than you're SOL as far as 3.08s go. If its a dana 61, than you could get 3.07s. I'm not really sure how to tell them apart though.

 

That is why I am 98% sure, I plan to read the codes off of it and decipher it that way, If I have to settle for a 3:55 it will still be an improvement over the 4:something, But I am sure thereare plenty of options, I will just be happy to have the truck run more smoothly at highway speeds(70) without it sounding like the engine is going to jump out.
for the trans service I am taking it to a trans shop, and I plan to question them about the rear axle, and performing the swap for me.
Now if I could just make it 4wd. . . .. . . . . for a reasonabe price!