For those who still google- Read this

Ls3 and ls7 (gold blade) throttle bodies are one in the same they are compatible for years 05,06,08,09 LS4s

If you have a 07 at this time ls2 (silver blade) is the only one compatible.

the harness for TB swap is only needed for 05 to 07 ls4s with 8 pin connectors which need to have 6 pin for the tb upgrade. All 08 and up ls4s are a direct plug in since they are 6 pin.

EDITED: first off thanks to fieroguru, DavidGXP, and GXP25 for their research in this area the FSM GXP25 provided was the last unknown for this swap turns out my alldata Ls4 wiring diagram was wrong, so i deleted it out of the original post please disregard quotes of the orginal in posts mentioned below..

**This is a general guide ALWAYS verify your year TB pinouts first**

PINOUTS ARE AS FOLLOWS

LS2 GTO TB . LS4 TB
PIN A ---- PIN F
PIN B ---- PIN E
PIN C ---- PIN H
PIN D ---- PIN A
PIN E ---- PIN B
PIN F ---- PIN D

NOT USED PIN G&C ON THE LS4 HARNESS

**If you have idle surge or hanging idle see post#10






PARTS LIST:

TB adapter here 55 USD http://www.alpermotorsports.com/inde..._detail&p=1688

Pigtail: LS2 Throttle Body Pigtail Brand New LS2 TB Pigtail | eBay

Throttle body: Ebay got mine for 140 shipped

all bolts are m6 x 1.0 you will need 4 for the TB and 3 are included with the TB adapter to the intake manifold

Thickness of LS2 TB for bolt length


Adapter

 

Looks about right. Strangely my impala came with a 6 pin connection when i bought it. So when i do my ls7 upgrade I'll be fine.

 

let me know how the ls2 swap goes! I want to do one too

 

Exactly thats why i was looking for someone with alldata or something to veryify the connector view with the one i obtained, there are alot of LS2 variants on this site and others and for the life of me finding a simple connector view of a 05-06 GTO seems impossible

 

Confirmed working

 

What intake are you using?

 

Ls1 its just sitting on my factory intake wanted to make sure the blade wasn't touching any part of the adapter

 

For issues with idle like i eventually had you will need to adjust 2 tables in the pcm

etc area scaler

for LS2 silver blades 4725.00

for ls3/7 use 5350.00

ETC scaler and Base idle airflow need to be adjusted to get you idling right.
here are the values i used with good sucess results may vary.

 

is the ls7 tb the same?

 

Depends on the year iirc don't go past 08 and if the tb has a silver colored blade it won't work right the brass tb blade moels are similar and should work but not tested so you should do the research and find out.

 

Just got my LS2 throttle body in today and on my 08 GXP there was no need to repin. It plugged right in and the blade moved with the pedal just fine.

 

indeed i just verified your circut numbers and its a match so i guess guys with the 6 pins have no need for repinning.

 

Does that TB bolt on the stock ls4 intake or do have to modify it?

 

No you will need a TB adapter to make fit

 

Where do you get the adapter for it.

 

you want to upgrade intakes first LS1,2, or 6 and then you have the option of using a ls1/6 TB or LS2 TB

 

Will those bolt directly to ls4 or do I need to do something else. I have an 07 Chevy Monte Carlo as.

 

you will need a throttle body adapter and a way to tune. but you wont see much gains with a stock intake manifold cause of the restrictions right inside the ls4 intake

 

If I got an ls1 or ls6 intake will they bolt on without any modifications. Also do you know which one would be better than the other. Would I need to get the whole fuel rails, injectors, and and throttle body. Sorry if I have a lot of questions. I'm used to the 3800 platform. This is my first LS engine.

 

sounds like you need to do some more reading through the stickies in this section of the forum.......so....cause i can i am not going to justify this question with an answer