Murphy Speed

Does anyone know what upgrades were done to the Joe Gibbs autos. Servo??? There is many upgrades to the 2005 Tahoe but I was wondering what they are so I can make decisions as to what needs to be done. The obvous changes are the Ground Force drop suspension 3" Corsa cat backs, Supercharge with the k&N, Baer eradispeed rotors, PCM Tune to name a few

charlie_gonzales

iTrader: (11)

+1 I'd also be interested in knowing

Gadgetized

iTrader: (9)

Check the manual from Magnuson.

http://www.magnusonproducts.com/pdf/manual-JoeGibbs.pdf

Page 56 is where they start to talk about the tranny. That is good info if you are looking for what was exactly done. If you want to upgrade your truck I say to have the tranny completely rebuilt, or switch to the 4l80e. I will be doing a 4l80e this week.

twinscrewsupercharger

What modifications did you have to do to your truck to fit the 4L80e?

Gadgetized

iTrader: (9)

I needed:
tranny
crossmember
tune
driveshaft
extend cooler line
flywheel

I got extra:
converter
full exhaust system
I used my stock dipstick and tube after I made it to install while the tranny is still in.
I made a shift cable bracket

I more than likely will get:
extra capacity tranny pan
larger oil cooler
converter/flywheel dust cover

I think that's everything off of the top of my head. I actually just got it running, and will hopefully take it down the road when I get the exhaust completed.

twinscrewsupercharger

How much did it cost you for the things you needed? I got an 04 Joe Gibbs Extended Cab Silverado and I'm thinking of going with the 4L80e since I'm thinking of putting 100rwhp over the stock rwhp. I'm a novice at this but may I ask what gears came with this trucks?

Gadgetized

iTrader: (9)

You need to check your codes in the glovebox or check the rear end to find the gear ratio.
The ratio codes are:
GQ1 -- AXLE REAR, STD RATIO

GT4 -- AXLE REAR, 3.73 RATIO

GT5 -- AXLE REAR, 4.10 RATIO

GU4 -- AXLE REAR, 3.08 RATIO

GU5 -- AXLE REAR, 3.23 RATIO

GU6 -- AXLE REAR, 3.42 RATIO

G80 -- AXLE REAR, LIMITED SLIP (POSITRACTION)

Or you can jack the rear end up, and turn the wheels one complete turn while counting revolutions on the driveshaft (if it turns around about 3.75 times you have 3.73's).

Plan on spending 2k to do the conversion. You will have to decide how you want it done, and where to spend extra money. For example I traded some parts and money for my Performabuilt converter, and decided to go with a Denny's driveshaft for piece of mind. Just a stock 4l80e is way better than the stock 4l60e, but don't forget you will lose HP as it is harder to turn. Most people would only suggest for you to have a 4l60e built because you won't have to buy a shaft, change the crossmember, dipstick, cooler line, and tune. If you are handy with a welder, you can save a big expense on the work.

twinscrewsupercharger

Thanks for the info. I hope everything goes well with your 4l80e swap.

Gadgetized

iTrader: (9)

Thanks. I will let you know, I should be driving it down the road on Wed or Thu this week.

radonfl

Sorry to hit an old post but i have a question about your post. Are you trying to say all JGP equipped rados came with 3 inch drop? I have an 05 and would like to lower it but it doesnt appear to have a 3 drop. It does sit slightly lower than others but not 3". What is the height of a stock JGP? Any help

Thanks