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CK5
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Big Red - 1990 GMC Suburban Ford Super Duty Dana 60 Swap
- Thread starter Hogback Fabrication
- Start date
Hogback Fab R&D rig
I bought this 1990 GMC 1500 Suburban at the end of 2023 as an R&D rig for various things, but mostly the front coil conversion and '05+ Ford Dana 60 swap.
It started out bone stock and worn out, the 700R4 transmission only worked in 1st/2nd. So I grabbed my trailer and headed up to Dinosaur, CO and picked her up.
It started out bone stock and worn out, the 700R4 transmission only worked in 1st/2nd. So I grabbed my trailer and headed up to Dinosaur, CO and picked her up.
Went and grabbed some build goodies, rinsed them off and got them in the garage.
Front and rear axle (not pictured, but picked up at the same time) are from a 2009 F250.
YMMV, but I paid $700 for the front axle and $200 for the rear. They're super common in junkyards and for most intents and purposes, are the same from 2005 to current.
Transmission is a 4L80E and transfer case is a driver's side drop NP241 from an IFS (88-98) Chevy (thanks @captron).
I also bought a set of stock takeoff tires/wheels for $200. There are options on stock tire size for '05+ Super Duty's, these were ~33" tall.
Front and rear axle (not pictured, but picked up at the same time) are from a 2009 F250.
YMMV, but I paid $700 for the front axle and $200 for the rear. They're super common in junkyards and for most intents and purposes, are the same from 2005 to current.
Transmission is a 4L80E and transfer case is a driver's side drop NP241 from an IFS (88-98) Chevy (thanks @captron).
I also bought a set of stock takeoff tires/wheels for $200. There are options on stock tire size for '05+ Super Duty's, these were ~33" tall.
The truck was stock but had a decent bit of hackery, this y-pipe didn't get reused 
It had a mystery 305 in place of the stock 350, still had TBI. Ran and drove but the transmission was bad, guy had been driving it until the transmission went.
It had a mystery 305 in place of the stock 350, still had TBI. Ran and drove but the transmission was bad, guy had been driving it until the transmission went.
I also picked up this cheap donor, 2002 Escalade for its LQ9 6.0L engine.
The Escalade ran and drove, the engine seemed good so I bought it. The rest of the truck was absolute trash, the ad stated that *for $150 in bulbs at Autozone you could fix everything* (meaning that every light on the dash was on). Air ride was bad, crazy torque steer and popping noises from all over the place.
So out the engine/trans/t-case came along with the wiring harness and the rest was sent to scrap.
So out the engine/trans/t-case came along with the wiring harness and the rest was sent to scrap.
An LQ9 is a gen III LS-based 6.0 engine, it has a few special few things that make it the HO option but the biggest are flat top pistons that give it 10:1 compression and a good bump in power compared to the 6.0L that normally came in pickups.
As gross as this thing was on the outside, it was mint inside. Cylinders still cross hatched, bores that were less than .001" out. In case you wondered what nearly 1/4 million LS bearings look like:
This engine had never been opened and this is pretty typical of newer engines in my experience. Much harder block material along with no carb/choke to send raw fuel through the engine mean the bores last way longer.
Another cool thing about these are the connecting rods. They're powdered metal (literally powdered metal heated and pressed/forged into shape) that gives them a really consistent grain structure. As such, they use fractured caps on the connecting rod. The connecting rod is forged as one piece (including the cap), then they machine the bores, and finally fracture the cap end. Basically they can make the rod "break" precisely and no material is lost, so they fit back together perfect.
As gross as this thing was on the outside, it was mint inside. Cylinders still cross hatched, bores that were less than .001" out. In case you wondered what nearly 1/4 million LS bearings look like:
This engine had never been opened and this is pretty typical of newer engines in my experience. Much harder block material along with no carb/choke to send raw fuel through the engine mean the bores last way longer.
Another cool thing about these are the connecting rods. They're powdered metal (literally powdered metal heated and pressed/forged into shape) that gives them a really consistent grain structure. As such, they use fractured caps on the connecting rod. The connecting rod is forged as one piece (including the cap), then they machine the bores, and finally fracture the cap end. Basically they can make the rod "break" precisely and no material is lost, so they fit back together perfect.
Bores were honed, new rings/bearings/seals and put it back together. I did put in a smallish Summit Racing cam as well.
Engine in!
Our LS swap motor mounts did the trick, placed the back of the engine in the same place as stock.
I also put on an aftermarket bracket from Chap Performance ($100-ish) to use the original Suburban A/C compressor, fit right in the same place. Same lines and everything.
Our LS swap motor mounts did the trick, placed the back of the engine in the same place as stock.
I also put on an aftermarket bracket from Chap Performance ($100-ish) to use the original Suburban A/C compressor, fit right in the same place. Same lines and everything.
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Front axle mocked up
Can't wait to see the axle and suspension install.
On to the good stuff!
The frame side bracket goes under the stock body mount and uses the existing rivet holes. This sets axle location front/back too, so no guessing on where this stuff goes.
These are built around the stock Ford radius arm, there are tons of aftermarket ones available too. I didn't have stock ones and found these Tuff Country arms super cheap new.
The frame side bracket goes under the stock body mount and uses the existing rivet holes. This sets axle location front/back too, so no guessing on where this stuff goes.
These are built around the stock Ford radius arm, there are tons of aftermarket ones available too. I didn't have stock ones and found these Tuff Country arms super cheap new.
been eyeing your coil SD setup on your site. Very cool.
Whats the WMS on the ford 60?
Whats the WMS on the ford 60?
The frame side coil mounts bolt into the top, side and bottom of the frame. Nearly all of the holes in this bracket are existing in the frame with a few added for strength.
(Coils wraps look weird because these are dual rate coils)
(Coils wraps look weird because these are dual rate coils)
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The crossover steering for this and the panhard bar will be available shortly. The crossover steering does require swapping to a 2WD steering box, but bolts to the axle as-is.
Paint, Summit Racing Viper Red single stage
And this is pretty much how it sits. ~2-1/2" lift up front, our 3" shackle reversal and 1" block out back (yes, Suburbans sit really low in the back).
Runs and drives great, definitely some soft springs (it does have a windshield now
).
Runs and drives great, definitely some soft springs (it does have a windshield now
).
I’m really digging the easy bolt in-ness of this setup….one of the big hang ups of the super duty axle is steering geometry
This was a cool panoramic shot from my backyard of a storm from this spring. If you're curious about the company name, the Grand Hogback is a long ridge of mountains that you can see in the background.
That was the idea from the get-go, make it easy to install.
Everything is located off of existing bolt holes so you don't have to think about where stuff could fit. Put it on and that's where it belongs.
The whole deal, steering and everything, is bolt on. No welding, no cut/fit it yourself.
