PROJECT HELP

[Gdsmith07]

Alright I've decided at this point if I'm going to work on my truck I'm gonna play with it a little. She's a 2003 Silverado z71 LT EXT cab 5.3 Vortec. I've got some questions on Thai project I'm preparing to dive into. The reared what is it exactly, how can I find out. And depending one which one what's the max power I can apply to it. And what would be a good replacement. The transmission would be the same question what's the safe limits. I rebuilt the transmission a couple years back and upgraded the rings and cylinders to hold more power and a harder locking shift. The engine I'm planning on getting a a set of aftermarket heads, manifolds, camshaft, high pressure injectors high pressure fuel pump aftermarket intake manifold larger throttle body. I'm trying not to go to over the top because I still use the truck daily just want a little more fun out of it. Right now there's a custom exhaust system under her but I'll probably end up replacing it. Planning on tearing through the 5.3 for a rebuild haven't decided on a bore, strike yet or if I will. If so what's the safest bore on the 5.3. All in all wrap it up with a tune job and probably aftermarket tuner, and a stall converter. Any add ins from project guys or gear heads would be great or what I need to beef up in order to hold that I haven't mention. Until I start to work on the body and such since she was used as a daily driver for years she will look a little rough, just want to get her back up to, and beyond, how she used to run. Right now she has 250k miles on her having some troubles with a cylinder missfire and instead of waiting for more issues to come in her older age I've decided to get ahead of them and bring her back. Thanks guys

[xXZ-71Xx]

Look in your glove box for these codes to get started

 

G80 : AXLE POSITRACTION, LIMITED SLIP
GU4 : AXLE REAR, 3.08 RATIO
GU5 : AXLE REAR, 3.23 RATIO
GU6 : AXLE REAR, 3.42 RATIO
GT4 : AXLE REAR, 3.73 RATIO
GT5 : AXLE REAR, 4.10 RATIO

 

I'm sure it is a 10 bolt but to be positive count the bolts on the diff.

[Gdsmith07]

Alright I'll take a look at it tomorrow. Any idea on what can be applied to that power wise in a safe range or what a good swap would be with minimal chopping and cutting.by what I've heard the G80 is actually a very dependable rear end as long as it's taken care of.

[xXZ-71Xx]

I'm not sure about how much power it can handle maybe someone else knows. I have liked the G80's I have had. I don't think a 14 bolt swap looks too bad and it should be able to handle more abuse, Move spring perches and switch to a modified 2500 drive shaft I think is all that would be needed.

[Chris]

I'm not sure about how much power it can handle maybe someone else knows. I have liked the G80's I have had. I don't think a 14 bolt swap looks too bad and it should be able to handle more abuse, Move spring perches and switch to a modified 2500 drive shaft I think is all that would be needed.

14 bolt is more time and money than it is worth. You can build the 10 bolt to handle power. As for bore and stroke. The 5.3 can go to 383 CI safely. A 6.0 swap would probably be easier and quicker power. That is 364 CI. An LQ4 with a blower will out perform what you want with your 5.3.

[Gdsmith07]

Alright I've got the g80 by what this sticker code says. I also took a picture if there's more questions on certain codes. What all would it take to build the g80 up? the modified 2500 drive train has crossed my mind I know my transmission is rated stupid high on horsepower and torque for what it's being put against right now. The 6.0 swap isn't a bad idea, but would it be a fare swap to a built 5.3? I guess if I swapped to the 6.0 I could always build it up. I was trying to figure out what heads to go with exactly right now any ideas ?? I'm planning on getting a larger throttle body and running a dual cold air intake. Run it naturally aspirated for now beef it up if i want. I'm trying to keep the four wheel drive system completely useable any ideas on if i have to upgrade the transfer case ?? It was just completely torn down and rebuilt with upgraded heavy duty parts around 20k miles ago.

[Chris]

Alright I've got the g80 by what this sticker code says. I also took a picture if there's more questions on certain codes. What all would it take to build the g80 up? the modified 2500 drive train has crossed my mind I know my transmission is rated stupid high on horsepower and torque for what it's being put against right now. The 6.0 swap isn't a bad idea, but would it be a fare swap to a built 5.3? I guess if I swapped to the 6.0 I could always build it up. I was trying to figure out what heads to go with exactly right now any ideas ?? I'm planning on getting a larger throttle body and running a dual cold air intake. Run it naturally aspirated for now beef it up if i want. I'm trying to keep the four wheel drive system completely useable any ideas on if i have to upgrade the transfer case ?? It was just completely torn down and rebuilt with upgraded heavy duty parts around 20k miles ago.

Larger throttle body will do nothing unless you are running boost or a donkey dick cam. The g80 can go in the trash can and run the Detroit Truetrac. The LQ4 with LS6 cam and 799/243 heads, and tune would be a decent combo good for over 350 HP and still run decent on 87 octane if needed. Cold air has little effect on power. The G80 is the weak point in the axle. The 4L60E will be a weak spot as well but you can get an aftermarket unit made to hold more power when the old one blows.

 

As for the engine suggestion i just gave. It is a decent budget build with room to grow.

[Gdsmith07]

Alright so go with the Detroit locker ?? And the transmission I rebuilt and built it for more power, torque to be applied to it. I guess if I feel in a while she starts to give a little I'll replace it. So would it be better to just go buy a 6.0 and run through it or build a 5.3. I mean I don't really want to buy a 6.0 and then build it after a while. I guess I could go a head and pick one and start to work on it. I mean what would be the power difference between a built 5.3 or bought 6.0.

[Chris]

Buy and rebuild the 6.0 before dropping in. In the long run it will be better

[Gdsmith07]

Alright I'll start looking for a 6.0 to buy, any input on what I should go with parts wise that'll beef her up.

[Chris]

What i listed should give you a decent bang for buck.

[Gdsmith07]

Alright guy I'm gonna get to work on buying stuff up. I'll keep you guys updated, post some pictures and such.