Has anyone installed a LS2/LS7 part # 12570790 GM throttle body on a 5.3. I am specificly talking about the LY5 5.3 that has the 4 bolt 87 mm throttle body stock. There are many other threads but most are about the old 3 bolt style.

My question is did you see any gains, loss. Any problems?

 

i have the LS2 i cant tell you if i gained but im sure i did. i have a better throttle response. ill run the truck on the 90mm an then the 87mm an see the difference

 

Im pretty sure thats the part number i have, ls7 tb, which appears to be slightly different than niffs ls2 tb... got it on the roush tvs so idk about on a na motor, but so far so good, i like it...

 

maybe im missing something but whats the advantage? its only a few MM bigger right?

 

yep.
3mm is better than not having those 3mm PLUS when you p&p the TB so it's more flow. the thing is your intake is already 90mm why not go with a 90mm TB?

ill make sure to do a 87mm and a 90mm run at the track and see what happens. unless when i dyno the truck Wed night ill try and see if they will let me dyno the 87mm vs the 90mm to see if it has any "difference"

 

^That will be a good test to see what comes out of it. I know someone dynoed a TBSS back to back with a 90mm and it lost 6-10 hp across the board; consensus was the different opening angle of the bigger tb didn't work well with the truck intake.

 

my truck isnt hurting if im whipping a 2010 camaro SS

 

^Wouldn't expect it to, on your bigger motor and big cam; i'm sure the 102 would even show good power on yours. But on a 5.3, either with cam, worked heads or even stock I'd like to see some back to back tests that show the 90 gaining something before I drop the coin on it.

I agree with you that if the plenum is 90, then a 90mm tb shouldn't hurt, and there's no reason it shouldn't make more power, if nothing else than at peak rpm.

 

well i figure on a stock motor you wont see a gain worth the money, but upgraded stuff and bigger motor itll be worth it. i dont have a stock motor to test the theory for you but i can test it on the 6.2 or you even if its done the cheaper way (track times)

 

About what I figure also. Do the 6.2 truck motors come standard with 87mm tb?