GMT 800 Brake Conversion > Silverado HD 2500

[davo727.b]

Maybe you were thinking of the gmt400 3500HD, they had 19.5 wheels and 10 lug rear and the front hubs omitted every other lug so it was 5 lug in front. Like a P30 bread truck chassis.

Guess it would take chassis and a lot of other stuff to make my truck into a true HD unit.
Probably leave it alone.

 

[dbrannon79]

if my good friend decides to scrap that 2000 express van box truck of his, I will have plenty of parts, front and rear, to convert mine over along with making it a dually too.

though I'm not sure what the advantages of having a dually or single rear wheels are.

 

[Will L.]

Duals for stability in towing. If you tow trailers now and get enough disruption in wind or rear tire squat that an extra 10% improvement would make a big difference- duals, keeping in mind they come at a price of mpg loss and 50% increase in tire replacement cost.

I did not tow big stuff that often-and only bumper pull at that. so I spent on magic hitch beans in stabilizers instead and got 3500srw trucks most of the time. It also saved on buying truck cost because dually always cost more than srw. Yes resale was lower but since buying was lower also- no money lost. Then things like drive through, tight corners, and off road were much better.

 

[MrMarty51]

Maybe you were thinking of the gmt400 3500HD, they had 19.5 wheels and 10 lug rear and the front hubs omitted every other lug so it was 5 lug in front. Like a P30 bread truck chassis.

Yup. I think that You are right.
Probably no chance of getting that package with the same wheel offset as what My truck now has so that if converting to that type of hub, maintain the SRW and the same foot print.

 

[Husker6.5]

Yup. I think that You are right.
Probably no chance of getting that package with the same wheel offset as what My truck now has so that if converting to that type of hub, maintain the SRW and the same foot print.

Nope. Not easily nor cheaply.

 

[MrMarty51]

Nope. Not easily nor cheaply.

Yup, kinda thought so.
$100.00 would be outta my price range.

 

[Husker6.5]

Yup, kinda thought so.
$100.00 would be outta my price range.

Out of mine too, right now!

 

[Dustin Zynda]

I've done a few of these now and I've found the easiest and best way (maybe not cheapest) is buying new moog lifetime lower control arms gmt800. They already have new bushings and ball joint, you do not have to ream anything. Gmt400 upper control arms then install kryptonite 6292 ball joints. The outer 2 holes line up, tack weld the rear then drill and bolt.
Kryptonite also makes tierods that are beefy and work great with gmt800 spindle to gmt400 center link.

 

[jrsavoie]

I've done a few of these now and I've found the easiest and best way (maybe not cheapest) is buying new moog lifetime lower control arms gmt800. They already have new bushings and ball joint, you do not have to ream anything. Gmt400 upper control arms then install kryptonite 6292 ball joints. The outer 2 holes line up, tack weld the rear then drill and bolt.
Kryptonite also makes tierods that are beefy and work great with gmt800 spindle to gmt400 center link.

Good post. Thank you.
Welcome to the club.

 

[Dustin Zynda]

Thank you, and thanks to M.Kasperan whom I believe did this first brake upgrade like this. I just didn't want to ream out the spindles or modify the tierods. In Tennessee I believe there is a state law about steering modifications. I just didn't want to risk it with modified tierods.

 

[davo727.b]

What are the details on the shocks and air springs? Torsion bars are removed? What dia wheels are those? Must be big as it makes the rotors look small.

 

[Dustin Zynda]

No torsion bars. Airlift builder series coilover, 3 inches coilover adjustable, 4 inches air travel. I'm still working with them, they take a lot of pressure to lift do to the weight. They are rated at around 2,000lbs, and have 30 plus adjustments soft to firm. I scaled out the front but need to figure sprung weight. I'm working on this for coilover, bags, or even hydraulic suspension.
I like a bit of a lift but being able to lower for getting stuff on the roof rack, into my tool box etc is a plus.
I have high articulating cv axles, wheels are 20's fuel forged.
With this new spindle you could go with ssbc calipers or wilwood even makes a brake kit
I'm also triangular 4 linking the rear with bags for getting into bed, hooking up trailers, and better ride.

 

[dbrannon79]

That looks like a mighty fine rig ya got there @Dustin Zynda! I am intrigued about these front shocks too. wonder if they make anything for the 2x4 rigs to soften the ride with those stiff front coil springs.

 

[Dustin Zynda]

Thank you very much, I love these trucks and making them new again with upgrades.

Airlift builder series shocks come in many different configurations. In your case with a 2wd, do you have a trunnion (the bar through it) on the bottom and a stud on the top?
Is your truck a big block?
Then you need the length, mount to mount the max compressed is a little under 11 inches and extended is about 15 inches.
2wd trucks have a lot more options and a lot companies for bags or decent coilovers.

 

[dbrannon79]

on mine, the LCA is a stamped steel normal control arm that the coil spring sits on with the shock going up through the middle of the spring. on the top side the frame has what I call a big upside down cup that the spring sits in with the shock up the middle with a threaded stud with bushings mounted on the frame. no trunnion unless I misunderstood what that is. in your posted pics, it looks like you eliminated the torsion bars on the LCA's. mine doesn't have torsion bars.

 

[Dustin Zynda]

Yes, I'm familiar with that setup. The picture of the bilstein shock should be what yours looks like? Airlift makes them in just about any configuration.

 

[MrMarty51]

A lot of nice information.
Thank You for coming in and posting those pics and information.
I see You registered in 2015 so I wont welcome You in as a new comer, just a welcome to one that came back in to share some information.

 

[DieselAmateur]

@Dustin Zynda thanks for sharing the info and pics, very nice looking setup. Those Kryptonite tie rod ends sure look beefy. So if I'm reading your post correctly the Kryptonite inner tie rods for GMT800 will bolt up to the GMT400 center link without modification?

 

[Dustin Zynda]

Thank you MrMarty51, I believe 2015 is when I found the first post about front brake upgrades. I started an electrical company that year and it took off. It has taken a lot of my time so I have not been able to participate in such forums.

I have always loved working on these trucks through the years, owning 3 crew cab long bed 4wd 454 trucks 97,99,00. 1 dually, 1 non, 1 was a dually but I changed the bed to a fleet side and rear axle to a 2002 14 bolt disc brake. and one ext cab short bed 4wd 454 97.
My daily is a 2015 duramax ltz z71 crew cab long bed this newer truck has given me more incentive to modify my older trucks. They really do not make them like they used to.

 

[Dustin Zynda]

DieselAmateur, that is correct. I purchased these because I wanted a strong steering component. With larger tires (33×12.5×20) not huge I'm always replacing front end part's.
They actually make them for 01 up trucks with an option to replace the center link on these newer trucks.
Reaming out the gmt800 spindle and modifying the tierods did not appeal to me and then using washers. I know gmt400 ball joints are larger and thank you to the guys that first did this conversion.
I searched and researched, found cognito and a few others that had the same set up before I found kryptonite. Other companies just sell the kit nothing separate. I called kryptonite they were very helpful. I explained what I was doing they said they would sell me tierods with the ends that I needed. Which are for the gmt800 spindle.
I thought that worst case that I would have to reem the center link but when I received them I realized they fit into the gmt400 center link
I will try to get better pictures of the tierods in the center link.