78/79 axle swap woe's

70sbudget · Jul 6, 2017

i recently purchased a 70 with a botched axle swap, or a swap in progress. there is a 78/79 high pinion under the front end that will require all new steering components, custom exhaust, an increase from 2" to 3.5" suspension lift and spring bucket spacers.

this will be a 90/10 street/trail rig. i recently purchased some used 35" tires and love the stance of this thing. however, at this point i can find no reason to justify lifting it another 1.5" just to use the front axle that is under it.

what are other easily obtainable axles that work for our front ends that dont require extensive costs and modifications.

broncodriver99 · Jul 6, 2017

Stock EB D44.

thegreatjustino · Jul 6, 2017

The high pinion will require the 3.5" lift. Anything less and you're going to smash the pinion into things underneath just pulling off of your driveway.

sykanr0ng · Jul 6, 2017

broncodriver99 said:
Stock EB D44.

/\/\ That +1 /\/\

You may, as many do, find that the differential hits the oil pan with only a 3.5 inch lift and should plan to use a 4.5 inch lift instead.

Full widths and 4.5 inch lift are excessive for 90% street use with 35 inch tires.

Rustytruck · Jul 6, 2017

1970 through 1977 Bronco Dana 44. If you can find a 1976 or 1977 you get the benefit of having disc brakes that will save you money later. You high pinion axle has value so you can get by without spending allot of cash on your replacement axle.

mgb0302 · Jul 6, 2017

Glad this post came up. I have full widths ready to swap in and have been told time and again that they just swap in (as long as you have a 3.5 lift- which I do). Has anyone here done the swap with only 3.5"?

70sbudget · Jul 6, 2017

Rustytruck said:
1970 through 1977 Bronco Dana 44. If you can find a 1976 or 1977 you get the benefit of having disc brakes that will save you money later. You high pinion axle has value so you can get by without spending allot of cash on your replacement axle.

what kind of value?

Apogee · Jul 6, 2017

70sbudget said:
what kind of value?

What part of the country? I got my HP D44 for $500, but it came with a running/driving '76 F150 on top of it, so I also got some parts for my '77 F150, a full width 31-spline 9", NP435 transmission and NP205 t-case out of the deal. The '76-'77 HP D44's had the thicker axle tubes and welded wedges, making them stronger than the '78-'79 units with the integral wedges. That said, I've seen complete HP D44's go for $150-$500 on various classifieds, Craigslist, etc.

thorgan · Jul 6, 2017

Hmm...this must be a problem only with the F150 Dana 44's. I have an F250 HP Dana 44 (from a '78) in my '69 with airbag suspension and my pinion does not hit the oil pan even when aired down all the way to the bump stops (which represents a height that's actually lower than stock). I had to get creative with my driver's side exhaust for driveshaft clearance but that's not really a big deal. Of course, you either need a 5 lug conversion of some sort or you need to swap in an 8 lug rear axle if you want to carry only 1 spare tire. I have an 8 lug Sterling in the rear because one of the main reasons I wanted the F250 axle was for the big twin piston calipers.

Food for thought

70sbudget · Jul 6, 2017

Well, guess the solution for now is the eb original front end I found locally with radius arms for $250 drum to drum with tie rods in place

langester · Jul 7, 2017

Sounds like a great deal and its local. Good luck with your project!

nvrstuk · Jul 11, 2017

You can make it fit!!! Is it worth it is the question only you can answer...

I have literally spent months stuffing a narrowed D 60 under a Bronco with only 2 1/2" of lift over stock. This is also with 6" of up travel and I'm doing it with 40" MTR's. It is a lot of work, clearances are stooopid tight... I mean I have literally less than 3/8" btw 5 major components at full compression and several are within 3/8" at ride height at full turn...

How bad do you want it!?

Good luck

lior72 · Apr 3, 2018

thorgan said:
Hmm...this must be a problem only with the F150 Dana 44's. I have an F250 HP Dana 44 (from a '78) in my '69 with airbag suspension and my pinion does not hit the oil pan even when aired down all the way to the bump stops (which represents a height that's actually lower than stock). I had to get creative with my driver's side exhaust for driveshaft clearance but that's not really a big deal. Of course, you either need a 5 lug conversion of some sort or you need to swap in an 8 lug rear axle if you want to carry only 1 spare tire. I have an 8 lug Sterling in the rear because one of the main reasons I wanted the F250 axle was for the big twin piston calipers.

Food for thought

Can you share some pics of your creativity

thorgan · Apr 4, 2018

Hmm...it seems that I don't have a single picture of what I did. The next problem is that my Bronco is in a garage 2 hours away at the moment and the exhaust has been removed.

Let's see if I can describe...
The heads (TFS high port) and the 351W deck height combine for clearance necessary to fit Fox Body Mustang equal length shorty headers. I think the ones I'm using are BBK. The collectors point right at the frame on both sides so the height due to heads and block makes a difference.

I also switched to a hydraulic setup to actuate the clutch lever instead of the factory linkage. My hydraulic cylinder attached to the T-case crossmember and reached forward to pull the clutch lever back. So, I was able to run the exhaust down tight to the bellhousing just forward of the clutch lever. Then I tucked it right up against the bellhousing directly below where the transmission bolts up in order to cross over to the passenger's side where it joined up with the other pipe for a 2 into 1 setup.

This provided plenty of clearance to the pinion although I did have to put a small dent in the pipe for driveshaft clearance right near the clutch lever.

As a matter of fact, this whole setup is going to be removed for a new setup since I imagine that none of it (except the headers) will fit with the 4R70W/Black Box i/NP205 combo that I'm preparing at the moment.

I'll try to get some pictures although it'll be a few weeks before I'll have time to work on it again.

nvrstuk · Apr 4, 2018

This isn't exactly what you wanted but here's some pics of a Hipinion D60 stuffed in (with only 2 1/2" of "lift" compared to typical coils ) but with 6" of up travel and 10" down.

The DS JBA header hit the pinion at full compression so I cut the flange off, welded in a 3" Power stroke down pipe (perfect radius) and after the pic had them re-ceramic coated since I've been running them for 7 years.

Similar but different on the PS.

I accidentally clicked/posted the 2nd pic... disregard it u less you want to see gusseting on the D60 knuckles...

nvrstuk · Apr 4, 2018

At full compression there are 5 critical clearances btw the pan, tie rod, track bar, track bar bracket, Pittman arm, ...super tight.

NC-Fordguy · Apr 4, 2018

nvrstuk said:
At full compression there are 5 critical clearances btw the pan, tie rod, track bar, track bar bracket, Pittman arm, ...super tight.

Will those tolerances remain the same when you take a hard drop?

nvrstuk · Apr 4, 2018

Yes, I'm running ORI's on each corner and that is the max compression with those measurements.

Jluck · Apr 5, 2018

NC-Fordguy said:
Will those tolerances remain the same when you take a hard drop?

Unlikely, things flex. I would run that little clearance on a vehicle that's going to be wheeled at all.

Digger556 · Apr 5, 2018

70sbudget said:
Well, guess the solution for now is the eb original front end I found locally with radius arms for $250 drum to drum with tie rods in place

Hang on. I have a '78-79 Bronco full width 44, which I believe is the same as the F150 unit. It is tight, but it fits perfect. One thing that might help you is, I'm running a Milodon oil pan. The pan cradles the axle nicely. I am running 3.5" of lift, however I have 6" of up-travel, only limited by the track bar. 7" are potentially there, but the axle can stuff just as far as the stock EB axle did.

Only mod that had to be made was moving the frame trackbar mount back 2" to clear the high-steer mod. I will dig up some pictures.

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