Would You Rather: SAS or lift, discuss amongst yourselves

[Littlebeefy]

Hi Snowpony,
I'm glad to hear you liked it in your application. Why did you decide to use the Dana 44 instead of the Dana 60?

There are several kits out there, many purportedly "bolt on". The Duff system you mentioned looks pretty nice (and I've heard good things about it from at least one other person who has actually used it) and it seems there are some pretty decent additional options:

https://dufftuff.com/product-category/full-size-bronco/sas-swap-packages-level-1-monster/

https://broncoair.com/sasInfo.php

https://www.skysoffroaddesign.com/collections/80-96-bronco-f-150-suspension/products/ford-sas-bf150?variant=19048852548

https://desolatemotorsports.com/shop/suspension/front-suspension/bronco-f150-4x4-straight-axle-conversion-kit-coming-soon/

https://protofab4x4.com/product/fullsize-sas-kit/

[ArdWrknTrk]

I imagine because the D44 has the correct 5 lug pattern to match the rear axle, takes a 15" rim and coil springs, unlike anything over #8,500.
... The F-350 where you'd find a D60 front axle.

[Littlebeefy]

Honestly, Jim, I’d sort of taken for granted that the 8 lug rear end would be more desirable and worth the trouble of installing with a set. Come to think of it, though, other than more options for wheels there isn’t really any benefit to the SD rear axle on such a short wheelbase truck, is there? Can you think of anything else that would make it worth the effort?

[ArdWrknTrk]

Super Duty, as in '99>?
Metric lug pattern?

My personal opinion is that these much bigger axles are much more unsprung weight, and would really harm bump response.
My truck tares at almost 6,700#, I can't imagine how harsh it would be in a Bronco.

[Nothing Special]

Like Jim, I don't want any additional height on my F-250 so I wouldn't do either.  In fact, I think I'm going to be looking for a less rusty crew cab soon, and if it ends up being an F-350 I very well might swap a TTB into it to lower it.

However, to follow the ground rules...  If I did want to lift my F-250 I'd do a SAS.  It's a simple bolt-on with stock F-350 parts.  And like Gary, I think the leaf spring TTB suspension is a terrible design (yes, I know I just said I might put it on an F-350...).

I probably would not do an RSK however, unless I wanted even more lift.  Yes it would likely improve the ride.  And if I DID want more lift that the ~2" an SAS would give I'd do an RSK.

On an F-150 / Bronco I'd definitely lift the TTB suspension.  In fact I did that on the '95 F-150 I used to have.  I think that gives better ride and handling than a solid axle.

The only reasons I'd want a solid axle on an F-150 is if I was going to use it for plowing, or if I was building it into a rock crawler or mudder and wanted big tires and stronger axles.  Then if I was doing it for a plow I'd go with a Dana 44 for the lower weight = better ride and handling.  Or if it was for off-roading I'd use a Dana 60 and probably a GM 14 bolt in the rear, giving up ride, handling (and affordability!) in favor of strength.

[Gary Lewis]

Actually, with stock rear suspension my SAS/RSK/SD spring swap slightly reduced the liftover height at the tailgate.  That's cause the front came up and the rear of the tailgate rotated down a bit.  Not much, but it sure didn't get higher.

[ArdWrknTrk]

As it it would if you had also installed the 350 blocks on the rear.axle.

I understand how the rotation about the rear axle centerline is going to reduce gate height by the proportion of the two distances.

133" V something like 48"

[Gary Lewis]

Yep - Didn't and don't want the taller 350 blocks.  Was thrilled when the front end came up level with the rear.  

[Littlebeefy]

It seems nuts to me but what it sounds like is if you wanted improvement in off road ability in the Bullnose Bronco, a vehicle that was ostensibly sold for its off road prowess, the best way to do it (back when it was new) was to replace the front end with the 78-79 Bronco front axle. Huh? Great job, Ford. Way to move the state of the art.

Clearly Snowpony has it down to a science but now I understand why.

[Gary Lewis]

Now you are back to the question of what you want to do with the truck.  If you want to do the Baja 500 you'll want the coil-sprung TTB's as they give the most compliant suspension and keep the tires planted.  They keep the un-sprung weight down on each tire and are more supple.  Lots of people still swear by them, although there are those that don't understand them that swear at them.

But nobody swears by the leaf-sprung TTB's.  

[ArdWrknTrk]

You've also must remember that the 250-350 trucks have a thicker frame.
And the 450's are thicker still....

A straight axle is easy to align and stays in alignment when loaded or unweighted.

The TTB is only 1/2 unsprung weight.
The other end is attached to the cross member.

[FuzzFace2]

Untill Snow said something I was thinking 4x4 straight axle and coils like they did in the older 4x4's as I thought they road pretty good and with the axle "C" cups you could get different degree to get the specs back in.

I like the straight axle as it is more robust for a 4x4 even for street use.
I had 230+ miles on my K5 Blazer and other than a few tie rod ends I did nothing to it.
My 02 Durango (IFS) with 240+ miles I have done ball joints, 1 hub bearing and Ujoint and I hate how mushy the ride is, like the shocks are always bad.

Also the last time I had it on the rack with new tires I was told if it does not hold all the adjustment things would need to be replaced because of rust! You don't have that with a straight axle.
Dave ----

[Littlebeefy]

I can’t help myself. I’m going to go take a look tomorrow. Other than exterior corrosion, what would you look for when visually inspecting a donor axle?

https://atlanta.craigslist.org/wat/pts/d/temple-1978-ford-150-4x4-swb/7227186936.html

[ArdWrknTrk]

Pinion backlash and play at the hubs?

[Snowpony]

 I used the Dana44 for two reasons, first I had one, got a great deal on it and it has the same wheel bolt pattern. I had just bought a set of 33" Duratracs and they were not cheap.
 Found lots of Dana44 options from brakes, axles, and differentials and I wanted to do the Duff kit, and there 44 was path of least resistance.
Bought most everything they had. 70/30 shocks, mounts, heim steering,springs,coil buckets,track bar,c bushings and the long arms.
Added an Eaton elocker and never looked back!
For my purposes this is great. I think the ride is better, but that just may be better spring rate?
 My tires rubbed the original TTB arms when the wheels turned right radius', and the Duff arms are made with a bend to allow tighter turning. Tires do not rub.I
My two cents

[Littlebeefy]

I think you talked me into it, Snow. The Duff kit is bolt on with no welding and minimal drilling and it sounds like everyone who uses it likes it. What gear ratio did you end up going with for the 33s? Also, what did you do about the rear end, leave it or upgrade to 9”?

Since you’re doing it again, what did you learn the first time around that’s going to change what you do the second time? Any “if I had only done that the first time” recommendations for people undertaking a similar effort?

Thanks!

[Snowpony]

My truck already had a 9" .
I still run the 3:50 gears, original tires were 31" tall. Not great out of the hole, but not horrible . Did have 35" in it and that was dumb. That really needed gears.
My Mustang has 4:88 gears, and that's a hoot!
Not highway friendly
When I do it again, front suspension will be almost exactly the same, may consider the upper coil spring mount that Ford put on it. My current set-up has the Duff upper spring mounts. No issue with the Duffs, just curious how it will set.
Rear axle on my current truck has blocks, my also try the shackle flip to also see what that looks like.
The other truck also has 33" Duratracs on a set of  10" wide Jackman wagon wheels,  also still running 3:50 gears 9" and Dana44 again too.
 Glad I sold you on the "Duff Stuff", wish they paid a referral fee! Ha Ha!
Curt