JoeyMiggs

Refurbished the entire interior dash by repainting it all a semi gloss black, wrapped the center console in black vinyl, looks brand new.
Painted small accent pieces to give it a more 2 tone look turned out great.
Deer hoof in my two doors, pancaked down the side going 35 MPH.





I've not been involved with the forums much, but I'll get to it and see what I can find out through you guys... I've got a 2002 Yukon Denali with the LQ4 6.0L which I've currently done the following to... The exhaust manifolds were leaking (snapped bolt head) so I installed BBK shorty headers on it, 1 3/4" I believe if not 1 7/8". Installed a cold air intake was originally K&N until the shop replaced the belts, water pump, and didn't install the belts proper so it ate through the intake tube.. They bought me a Spectre Intake and its' aluminum not plastic like the K&N... I've kept good maintenance on the truck, replaced all the O2 sensors, replaced the shocks with the passive Arnott suspension in front and rear that bypasses the auto-ride feature, put MOOG replacement coils in the rear (got an extra set they sent 2 pair), replaced the wheel bearings at a fly by night shop when out in Colorado (Midas, they told me my battery would leave me stranded in the wilderness and my wheels would fall off on a mountain pass, and I was high so I said DO IT!), Battery, etc...... The truck is quite the reliable beast, and I'm afraid if I begin to modify the engine more I'm in for some big surprises in reliability. I refurbished the interior from the dull cracked up grey that chips off and looks really bad, with semi gloss black. The interior is awesome! Installed drilled and slotted rotors, all new pads, and replaced all the brake lines..

I'd like to do the following before I beef up the motor at all...
Replace all upper and lower control arms with Moog replacements (they come with ball joints already there).
Replace the CV axles... (Funny clank when I turn a certain angle only sometimes think that's it, if not the ball joints, afraid it might be transfer case on AWD)
Lower the vehicle, and somehow install a manual air compressor for the rear shocks (the Arnott rear shocks that do nothing at all now that I've bypassed with a sensor)

I figure the suspension would be best to upgrade first and get proper if I'm beefing up the motor, right? On the motor...
TBSS intake manifold with 32lb. injectors already in it. (found it online used, wonder how those gaskets work? Not sure if its' compatible.)
Online I found 8 Accel 140040-8 LS1 Super Ignition Coils
8.5mm MSD Ignition wires
Magnaflow catalytic converter upgrade bolt on (1 piece from magnaflow)
Magnaflow cat back exhaust

These are little things that seem to be easy for someone like me, the hobbyist... Just wondering what anyone else thinks. I've looked at throttle body spacers, and I'm looking for something because after I replaced the stock exhaust manifolds with BBK shorty headers, and replaced the O2 sensors, plugs, and put a cold air intake on it... The vehicle is quite the beast, may have added 35 HP who knows? It's falling apart around the motor, which has 190k on it. Kind of long in the tooth but any input is appreciated. If my budget were infinite I'd pull the motor and have it professionally built with a Procharger on it, but I'm not that rich. Or I'll drive it into the ground as it is I'm not sure yet. It's a love hate thing not sure what to do. Sadly, I'm learning my engine is nearly worth as much as the truck as whole, kind of sad at 16 years old now.

Anyways, deer jumped into the passenger doors and the roof is fading bad, the roof might rust, needs a paint job, the rockers are rusted out, getting some rust above the rear wheel well.... and I'm just not sure it's worth it. I'm wanting a Corvette or something sporty so it's hard to get sporty in a 5,700 lb. SUV. Once had a Z-28 pushing 350 HP and I'd almost trade for one now...

JoeyMiggs

Little long and this is my first post, but in short, the headers are feeling like they want the exhaust opened up. The truck acts like the catalytic converters are clogged, creating back pressure perhaps. Not sure if anyone has a full exhaust from headers back solution for something like this, was looking at Magnaflow set up. Not sure if a new intake is worth it, the TBSS, not sure what kind of injectors I'd need, not sure if the coil packs and wires would make any difference. Not sure if I'd need to tune it thereafter or what.

FFDP

iTrader: (2)

The engine itself is very strong, it could handle 500-500whp no problem if you wanted it too. Past that the early engines become weak, so you have no worries there.

The TBSS or NNBS intake swap is a good upgrade, should net a little horsepower with the better flow design. Skip the coil packs and fancy wires, they will do you no good. Stock coils are hands down the best coils for these engines.

Injectors will want to be upgraded (stock 25lb/hr injectors max out really quick on modded 6.0's), if they come larger injectors use them. Make sure they are factory GM injectors with readable part numbers so you can figure out the exact flow rate. The intake swap, injector swap and further exhaust mods if you do them will require a custom tune and thus the want for known good injectors that have data. You'll likely need injector wiring adapters because they newer intakes run USCAR connectors.

I think the only real concern is the transmission. You aren't adding a ton of power and it should be fine but that is a weak link that could show it's age someday.

2002_Z28_Six_Speed

iTrader: (20)

By the time you dump money into the motor and tranny (and then what the rear diff?) you might start asking yourself if it is worth it?. With the massive weight of the SUV it will never be all that fast. I never felt much of a difference with bolt-ons. Motor swap did the trick though.

1FastBrick

iTrader: (17)

The biggest issue I see is the rust. Are you prepared to tackle that or spend the money to have it repaired? If not, It may be a futile effort spending money fixing everything else and add some power.

As mentioned the transmission is no spring chicken at this point. At 190K, You may find the next weakest link and that's not a cheap fix...

BudRacing

iTrader: (3)

Your description of the rust sounds pretty bad. But the pics don't really hint at it. Any photos of that? That'll really determine what's worth it. Considering the GMT800 SUVs are fully depreciated in the $4-5k range, it may be cheaper to trade out for one without any rust (from GA) and transfer parts as you see fit. I see them on Craigslist all day--kinda wish I had the space for one as it would be nice to have.

The following is what I would do given your situation:
Being a Florida truck, I'd ditch the 4L60 for a 4L80 and do a 2wd conversion. As long as you're not taking it out on the beach you won't need 4WD. It'll be a little lighter and more responsive in acceleration and also net you an additional MPG or two. Then you'll have a hardier trans and some peace of mind. You'll need the swap crossmember, a driveshaft, and some computer mods to make it work. Pair this with a cam which needs a tune anyway, and it's well worth it. I wouldn't worry about injectors unless the tuner indicated they were insufficient or needed replacing. At that point I would contemplate decapping them. A little sloppier on the spray, and many would regard it as a hack mod, but it works in a pinch. Injectors aren't cheap unless you're sourcing from a junkyard.

At 190k, a cam swap is actually a good thing. You're practically rebuilding the top half of the engine while doing a cam swap. Lifters, trays, gaskets, valve springs, rocker bearings, oil pump, timing chain--all things you might as well swap out "while you're in there." Since this looks like a daily driver, I'd stick with a mild truck cam to run with a stock torque converter. BTR or Cam Motion Stage 1 or 2 truck shaft.

I prefer cat converters on my cars, so I'll leave that up to you. However, I'd probably run inexpensive high flow cats if they did need to be replaced and replace the muffler with a Borla Touring catback.

For suspension, I would consult Tony aka Norcal SS. He's got a lot of experience, good taste in parts, and will also sell you a package deal. He may even be able to set you up with TBSS intake or at least point you to someone that has one.

2002_Z28_Six_Speed

iTrader: (20)

yup. you can get up some icy hills from a dead stop with just rwd and good tires. dont need 4wd.

JoeyMiggs

There's no doubt the rust has me a little worried. It spent the first 10 years of its' life in Northern Illinois so it isn't even a Florida truck, just got here actually. The winters up there are brutal and the truck has just been a rock solid driver. Very little in maintenance cost, and it has a lot of life left in it. Like I said I'm looking for something sporty, wanting to get a WS6 Trans Am or SS Camaro perhaps. The only thing which brought me to these forms was researching my LQ4 engine. I see people doing the LQ4 swap into 3rd Gen. Camaro's and Firebirds. The truck is still good, not going to buy a roller and yank the motor just yet, as this Denali likely has another 85k miles in it. Maybe I should buy a 3rd Gen roller and get myself a nice used LQ4 or LQ9 if I'm looking to play with the motor. I'm trying to justify dumping any more money into this vehicle at this time, and with the rust, door dents, it just isn't my show truck I dreamed of. It would take a frame off restoration on the body and likely $15,000 to $20,000 or more in parts and fabrication to get it to that dream DUB Denali. It's just not happening for me there. It's booking for $3,500 to $4,500 and it's worth a good $6,500 or more to me, best vehicle I ever owned. I've dreamed of it being this low down sporty 6 speed, but I'm thinking a real TrailBlazer SS is my best option if I'm looking for a sporty SUV. It just isn't the Corvette I wish it were.