1985 Ford F150 4.9L 4-Speed 2WD Regular Cab LWB
1984 Ford F250 6.9L C6 Auto 4WD Regular Cab LWB

I have the F250 as a donor truck for the air conditioning and rear axle that I'm wanting to put on my 85 F150.

I've not been able to successfully measure the distance from the spring hanger to the shackle on each of the trucks, but I'm hoping that the distance is the same.

Will I be able to just swap the spring pack and axle, or will I have to swap the hangers and shackles, also?

BTW, will I be able to get dual-wheel simulators to work with the rear 8-bolt pattern and the factory 5-bolt pattern on the front of the truck?

Thanks for any suggestions or insight!

Nightrain

 

I *think* that you have to swap shackles/hangers as well, as the 4x2 F-150 probably has 2.5" wide springs, and the F-250 should have 3" springs.

I don't know about the spring length. Since you have to swap the hangers anyway you can just relocate them if necessary.

You also might need a shortened driveshaft because of the much larger differential. Not sure, just something to look out for.

What is a dual wheel simulator? It doesn't sound safe to me. Wheel adapters and similar contraptions can sometimes compromise strength. If it were me, I wouldn't use one, but again I don't know much about them. The safest thing would be to swap the knuckles, spindles, and rotors over from a junkyard 2wd F-250.

If you do that, you'll basically have 3/4 brakes all around - so you might need the master cylinder & booster from your parts truck.

Also be aware that you not increasing the frame strength at all - and this is an important difference between a 1/2 ton and 3/4 ton truck. A BIG difference.

 

Let me see if I get this. You want to take a 2wd 1/2 ton, and change out the rear axle from a 4x4 3/4 ton, so the 1/2 ton can be a 3/4 ton truck? What is the condition of the 85? For the same amount of bolts, (actually less) that itis going to take to replace spring hangers, and shackles, why not swap bodies, and beds? Then your 84' will be rolling on a real 3/4 ton drivetrain, and it will be 4x4. Then you could swap over the a/c system. If the a/c system is good, then the tuck wasn't in a fire or anything, so the frame might still be good. Maybe???????

 

Ahh, meant to say dual wheel adapters. It's been a long day, and I'm getting kinda sweepy... lol.

The F250 is an ex-fire truck, and for some reason, the frame has been cut and poorly re-welded underneath the rear of the cab. I don't know why this was done...

But now, it's a scrapper.

I just wanted a little extra "beef" for the rear suspension and axle. I don't do a whole lot of pulling... Maybe the heaviest load being a Ford 4000 tractor and 6' disk.

Nightrain

 

If you wanted to beef up the rear axle, consider swapping in a 9" with aftermarket axles. Then you get to keep your wheels. Less work, and a built 9" is very strong.

 

the 8lug rear and springs will fit, there the same. the drive shaft might fit with the exception of a new u-joint since the auto has the big rear and the 4 spd. has the 8.8 one driveshaft might be too long and one might be short. but in any case you already have a drive shaft it will just have to be shortened