so i recieved a free 90mm off of an LS7 motor. i would love to swap out my factory throttlebody with this one, and will be doing a camswap at the same time. this will be on my 07 GMC sierra 5.3. however, i am quite sure that this throttle body will not fit, and will require either modifying my current manifold or getting a new one, to clear the 90mm butterfly. so, seeing as how i searched to no avail, and you guys seem pretty sharp, which manifold can i swap out for, that will allow me to continue to run my accessory setup.

side note, it would not suprise me if i will have to rewire or repin my harness to plug the throttlebody in, thats not too much of a concern, and will deal with that when it arises.

 

The LS7 has a different port design (Retangular) vs our cathedral ports. If you ran L92 or LS7 heads you could. But then you would have a 4.000-4.125" bore for the valves=motor swap.

 

You have 3 options i know of. #2 and #3 require a good bit of work to convert to a car manifold, which you can find plenty of info about if you search "LS6 intake swap"

1. Use an LS2 truck (SSR) intake manifold, this would be the cheapest and easiest by far, but least performance of the options

2. Use a professional products Typhoon intake

3. Pick up a FAST 90mm intake.

 

I thought the new 5.3's already had a 90mm TB on them... My friend's 07 Av 5.3 flex fuel has one on it. Maybe it's only the Flex Fuel ones that get it? Or only Av's?

It's the TBSS style 90mm one, with a different pinout and different internal resistance than the 90mm Vette TB though, so more than a repin would be needed. Not to mention no performance gain from one to the other.

 

well i will have to check my current size, to see if it was worth it. i figured i would have to go with a TBSS mani, but i didnt know that the internal resistances were different too. oh well, i guess i can sell the throttle body. we literally had it laying around the shop from a race car we built this past summer.

i will have to check on the resistance for sure, as well as the size of the factory unit, and see if a ported TBSS mani will work