AWD 99 2 Door Tahoe Build

[Jnunez74]

Got another free moment to share a bit, so following the painting of the firewall, the body was put back on the frame and the real challenges began. To start with, the transmission crossmember had to be relocated farther towards the rear to allow for proper mounting of the transmission and Tcase.

You must be registered for see images attach

Once the drivetrain was properly fitted and secured, the next challenge was had.

You must be registered for see images attach

you can see in that picture how far out the camber was. The geometry of the front suspension was not ideal in anyway, as no adjustment could bring the top of the tire in far enough to allow for alignment. After some head scratching it was decided that shortening the uppers would give us the necessary adjustment, so they were shortened by an inch. This was done by a local machine shop and the results were as desired. More issues came with the driveshafts as these component’s utilized e different Ujoints. After trying to find conversion joints to utilize the stock shafts, it was decided to just get new shafts cut and skip all of the conversion nonsense.

You must be registered for see images attach

For exhaust, we trailers the truck to New Orleans and had Custom Muffler install dual 3” stainless pipes with Borla Pro XS mufflers. Eventually the goal is to do side exits before the rear tire so I had them turn it down before the rear diff.

For cooling, I couldn’t find any affordable options for radiator and fan combos that were reasonably priced so we opted to make our own assembly. A cold case radiator was chosen and paired with a Jegs dual 16” fan kit. From these two, I drew up a cad file of a shroud and had it made by our sheet metal guy out of aluminum.

You must be registered for see images attach

I wanted to utilize the trans cooler on the radiator but my Transmission shop insisted that I use a stand alone system, so I strapped 2 40k coolers to the front of the assembly to handle keeping the 4l80 and 242 cool.

You must be registered for see images attach

More to come

I don’t have any pictures for this update, just words to fill in the progress.
To begin, my drive line angles were less than ideal so 4 degrees of shims were added to compensate.
Had to make power steering hoses, had 2 blowouts before that was finalized.
The fans are all wired in, they are ground switched by the pro flow system, so that wasn’t too bad. Figuring out where to mount the relays was a bit of a conundrum but they ended up getting mounted to the side of the passenger battery support.
Installed all vacuum lines (brake booster, pcv and fuel pressure regulator)
First start was a breeze, it came to life and boy does it sound knarly. Definitely not the choppiest or loudest but the Borlas definitely give it the more modern sound I was going for.
After adding fluid to transmission and setting up TCU, we finally got it moving under its own power. From the little testing I was able to do before having to go back to school, there was no binding in the driveline, and it seems as if the theory is now a working example. You definitely can swap gmt400s to a 9.25 without any suspension lift or modifications to anything other than the mounting points on the frame. There is another thread where I addressed the driveline.
All that seems to be left mechanically is installing the shifter for the T-Case and the Posilok cable to allow for diff engagement from the cab. Also have to address the parking brake as it currently is non existent.

On a side note the paint isn’t only gonna be the red velvet. Against what seems to be popular opinion, I am going with the traditional 90’s two tone. Where the original was silver though, I am going back with a gold accent. I believe it is Coppertino but I’m not entirely sure on paint code.

More to come when I can get more done

 

[Dravec]

beautiful part about the AWD conversation is that is isn’t all the time. I installed a 4x4 posilok kit to be able to unlock the front for cruising. As for an LS, I’m still not sure how I feel ab my decision lol. An LS would have probably been easier/cheaper to achieve 550hp but I really wanted the torque. Tryna have this thing be a nightmare for diesels from a dig

"Horsepower is how hard you hit the wall. Torque is how far you drag the wall with you."
I friggin love torque!

 

[Jnunez74]

"Horsepower is how hard you hit the wall. Torque is how far you drag the wall with you."
I friggin love torque!

From the little test drive I did, it definitely did not disappoint. The 350 was enough for this truck imo but the 460 made me feel some kind of way driving for the first time

 

[Jnunez74]

Small update, being 4 hours away at school has made progress a little bit slow, but I finally put some mileage on her. It did surprisingly well, did a few pulls up to 60 and probably had it on the road for an hour or so. Everything functions as expected, the disc brakes make it stop like I’ve never felt an obs stop before, and the suspension never bound up turning or had any issues.

I did it about half and half in the low and high range on the TCase just to see what it would do. In the low range it is an absolute animal and the high range isn’t far behind. Had a slight issue with the the transmission shift cable but after a little fab I was able to make a bracket that allowed for reliable shiftage.

One thing that has me stumped is the high pressure I’m experiencing in the cooling system. My upper radiator hose isn’t softening up at all, and it blew off on the first trial. I have a high flow thermostat in there but that didn’t seem to help it too much. If anyone has any ideas on how to address that it would be much appreciated. For background on that I have a high flow pump from summit and a cold case radiator. My inlet at the intake manifold is a 1/4 bigger than the outlet from the radiator making me thing the necking could have something to do with it but I’m stumped atm

 

[0xDEADBEEF]

Small update, being 4 hours away at school has made progress a little bit slow, but I finally put some mileage on her. It did surprisingly well, did a few pulls up to 60 and probably had it on the road for an hour or so. Everything functions as expected, the disc brakes make it stop like I’ve never felt an obs stop before, and the suspension never bound up turning or had any issues.

I did it about half and half in the low and high range on the TCase just to see what it would do. In the low range it is an absolute animal and the high range isn’t far behind. Had a slight issue with the the transmission shift cable but after a little fab I was able to make a bracket that allowed for reliable shiftage.

One thing that has me stumped is the high pressure I’m experiencing in the cooling system. My upper radiator hose isn’t softening up at all, and it blew off on the first trial. I have a high flow thermostat in there but that didn’t seem to help it too much. If anyone has any ideas on how to address that it would be much appreciated. For background on that I have a high flow pump from summit and a cold case radiator. My inlet at the intake manifold is a 1/4 bigger than the outlet from the radiator making me thing the necking could have something to do with it but I’m stumped atm

Get a regular flow thermostat.

I tried no thermostat and flow restrictors on my C5 track toy and it always ended up blowing the hose off. I tried all kind of clamps, double clamps, etc. Put a normal thermostat back in and it was fine.

Basically, there's no point trying to flow more than the radiator can handle.

 

[Jnunez74]

Get a regular flow thermostat.

I tried no thermostat and flow restrictors on my C5 track toy and it always ended up blowing the hose off. I tried all kind of clamps, double clamps, etc. Put a normal thermostat back in and it was fine.

Basically, there's no point trying to flow more than the radiator can handle.

I had a regular one in there and it won’t keep itself cool… overheats with no thermostat as well… water if the block isn’t dirty when I undo the upper/when it blew out, no particulate in there so I don’t think there is blockage… it keeps itself around 210 with the Mr Gasket balanced high flow which is fine but it seems to still be holding a hellacious amount of pressure

 

[Jnunez74]

I had a regular one in there and it won’t keep itself cool… overheats with no thermostat as well… water if the block isn’t dirty when I undo the upper/when it blew out, no particulate in there so I don’t think there is blockage… it keeps itself around 210 with the Mr Gasket balanced high flow which is fine but it seems to still be holding a hellacious amount of pressure

I haven’t seen how far past 220 it goes with the regular so I might throw it back in and try it. It seems that is has the same pressure with either in it but the HF is keeping it cooler. I don’t have the $$$ to risk any sort of overheating though so I have been conservative with testing. Only reason I got the balanced was bc my boy at the parts store did me a solid and gave it do me at 25% of MSRP

 

[0xDEADBEEF]

I had a regular one in there and it won’t keep itself cool… overheats with no thermostat as well… water if the block isn’t dirty when I undo the upper/when it blew out, no particulate in there so I don’t think there is blockage… it keeps itself around 210 with the Mr Gasket balanced high flow which is fine but it seems to still be holding a hellacious amount of pressure

There's a balancing act. If the water flows too fast through radiator it won't cool down,

 

[Jnunez74]

There's a balancing act. If the water flows too fast through radiator it won't cool down,

Could reducing inlet at the manifold help me out? I don’t see how it could as the outlet would determine flow rate but I’m willing to give it a shot if there’s a chance it’d reduce the pressure on that upper

 

[shovelbill]

"Horsepower is how hard you hit the wall. Torque is how far you drag the wall with you."
I friggin love torque!

Like a 5" arm 103" shovelhead ...