I've recently purchased a 00 tahoe limited and when I programmed it with my granatelli it said from the vin download that it had a 4L80E. Do all the limited/Z71 tahoes come with the 80 or did my tuner read incorrectly? I know the limiteds came with the police package with the larger brakes and such but does anyone have anymore info on the differences with my truck over the other trim levels? I've called dealers and searched all over for info but can't get a straight answer. Any help is appreciated.

 

What motor does it have?

 

5.7 Vortec, still the older body style.

 

They have a 4L60-E. The only differences in a Limited are:
- Roof rack delete
- Power steering fluid cooler
- larger front brakes
- 3.42 rear end ratio
- trans cooler
- 120mph speedo
- police package rear sway bar
- two-tone leather
- side moulding delete
- onyx black grille / bumpers
- fog lights
- ground effects
- unique Ronal R36 16x7 machined-face wheels

(The Limited is based on the Tahoe SS concept trucks, unfortunately it only got the looks, not the performance. There were several versions of the Tahoe SS concept before it made it into production as the Limited.)

It has a 5.7L Vortec L31 (350) with a 4L60-E transmission and a 10-bolt rear with a G80 and 3.42:1 gears.

I know these trucks very well, and of these details I am sure.

 

Thank you very much, I finally got some clarity on the subject. I wonder why my programmer read it as an 80 I guess I will be continuing my search for the added power, are the jba headers any good for these trucks or what combos work well na? (I plan on doing 4.10 with an eaton along with a custom tune, custom exhaust and some squeeze)

 

See for yourself. The 4L60-E pan bolt pattern is square for the most part. The 4L80-E has a tombstone shape - round at the rear.
Any headers work well with these trucks. Unlike stock Gen-III manifolds, the ones on the Gen-1e Vortec engines are restrictive and do not flow well. The JBA's will bolt to the existing downpipes requiring no fabrication or welding at all. When you order them you will be asked if you have A.I.R. or not. This can be determined by looking for small-diameter tube going into the front of both manifolds. The tubes connect up to hose that runs to an air pump in the driver-side battery tray. If you have A.I.R. (All 2000 Limited's have it to my knowledge) then be sure to get the right headers for it.
You are starting in the right place. The exhaust is way too constrictive. If you decide to do a cat-back keep in mind that there is a cut-out in the rear ground-effect piece for the tailpipe. Any aftermarket exhaust will need to exit in precisely the stock location with no giant blingy tip to fit right. Otherwise, you'd be looking at modification. Also, the rear floors in these trucks are not very well supported. They tend to act like a giant diaphram when it comes to noise. Keep that in mind when choosing a muffler - resonance is a serious issue.

 

I planned on running the jba's since I can get them for cheap through my work. Magnaflow makes a bolt on kit but the intermediate piping for my cats looks really restrictive so I planned on fabricating one with high flows at work and doing a single exit on the driver's side just under the rollpan angled down. I figure with a good tune, marine mani and 100 shot with a good converter and it might be halfway fun with some suspension work. Will the 4L60 last long or should I be looking for upgrades immediately since the truck has 100k (fluids changed and everything looked good when I pulled the pan).

 

Your truck weighs about 5600 pounds. These PCMs are not tuned with very much torque management and the L31 makes a LOT of torque down low. They drivetrain can take another 100HP and 100ft/lbs. without any complication, but much more nad the G80 (factory locker) blows first, followed by the transmission. The transmissions fail in so many different ways but at just 100HP more the hard parts will hold up. It will fail once the clutch materials are used up on the 3-4 pack.
Don't try to get any power out of it past 5000 RPM on the stock heads, the valvesprings won't support it.
The weakest link in the entire powertrain is the G80 differential.

 

I'm replacing the grenade loc asap along with yukon or precision 4.10s and alloy usa steel shafts. I figured I would start buying trans parts now and by the time I get to the headwork I'll have most of the spendy stuff purchased. Will new springs and a mild cam with a good port and polish be ok with the stock ecm or is it best to look at doing independent management on these trucks? Thanks for all the help dude, I have plenty to learn about these trucks.

 

The stock PCM is programmable. Curently only Jet Dynamic Spectrum Tuner is available, but hold out for another month and EFI-Live will support them.

The stock heads are easier to replace with the availability of all the inexpensive aftermarket choices for these. Aluminum, Iron, big valve and runner, little valve and runner, D-shaped exhaust ports or standard SBC exhaust ports... MANY choices.