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Is a 90mm throttle body a direct bolt-on for my 2006 5.3?
- A three-bolt 78 mm cable throttle body can be fitted to a Gen IV four-bolt intake with an adapter, but that can choke an engine designed for a 90 mm throttle body; the better option is an aftermarket four-bolt cable-actuated body with TPS and IAC provisions, such as the 92 mm Nick Williams unit. (applies to 0411; 2007-2013)
- A 92 mm Nick Williams cable-actuated throttle body with TPS and IAC provisions is shown fitted to a four-bolt TBSS intake as the recommended cable-throttle option for Gen IV manifolds. (applies to 0411; 2007-2013)
- The early Gen IV LS2 uses the E40 ECM with a completely redesigned four-bolt throttle body with a 90 mm silver blade; TAC functionality is integrated into the ECM, replacing the older P01 and P59 modules used in Gen III engines. (applies to E40; LS2; 2005-2006)
- The E40 ECM and the silver-blade LS2 throttle body can only work with each other; identify the E40 by its tall black connector plus short blue and gray connectors, versus the E67's short blue connector plus tall black and gray connectors. (applies to E40; LS2; 2005-2006)
- GM made three Gen V LT throttle body sizes: 80 mm for 5.3-liter trucks and SUVs, 87 mm for 6.2-liter trucks and sports cars like the Camaro and Corvette, and 95 mm exclusive to the supercharged LT5 in the 2019 C7 ZR1; each has its own mounting footprint, so swaps often require an adapter plate or a different intake manifold. (applies to E92; L83, L86, LT1, LT4, LT5; 2014-2019)
- ICT Billet 551567 adapts a three-bolt 75 mm electronic (DBW) throttle body to a four-bolt intake (TBSS/LS2/LS3 manifolds), with a 102 mm intake port; it is for DBW bodies only, not mechanical cable bodies, and does not fit the LS4 intake. (applies to LS2, LS3; 2007-2013)
- ICT Billet 551513 adapts a three-bolt LS intake to a four-bolt throttle body, works with DBW or cable bodies, has a 75 mm through-hole tapering to 92 mm, and bodies above 92 mm need spacer 551517 plus longer bolts.
- ICT Billet 551560 adapts an LS4 intake to a three-bolt throttle body (DBW or cable), with a 75 mm opening. (applies to LS4; 2005-2009)
- GM 90 mm LS2 throttle body 12570790 is a four-bolt DBW unit for 2005-2006 LS2 Corvette, GTO, and Trailblazer; seller notes say the harness plug changed in 2007, implying 2005-2006 versus 2007+ wiring differences. (applies to E40; LS2; 2005-2006)
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Confirm against the instructions for your exact parts before wiring. More: Throttle (drive-by-wire) in our tuning guide.
No, it doesn't bolt straight on. The 90mm throttle body (PN 12605109) needs a Trailblazer SS intake manifold or a 2007+ 4.8/5.3 truck intake. On a stock truck we don't recommend it, because the 75mm throttle body already flows about 63 lb/min, which is enough for roughly 630 hp. The 90mm, at about 80 lb/min (~800 hp), only pays off with a bigger cam or forced induction.
Check this first:
- Which intake manifold is on the engine now
- Whether the build has a cam or forced induction that needs the extra airflow
- That the throttle body matches your computer: 2005–06 electronic throttle bodies are paired with specific ECMs
Based on what we've seen work across our own builds, our friends' builds and the wider LS community, reviewed by our lead shop tuner (over 20 years of LS and LT tuning experience). Every combination is different, so use at your own risk and check our safe tuning limits before any wide-open pass.
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Every option we know of
| Maker / product | Part # | Fits | Price | Where | Status / notes |
|---|---|---|---|---|---|
| GM / ACDelco Gold-blade throttle body | 12605109 / 19420707 | Later DBW applications | about $150-250 | Buy dealers, RockAuto | Current production Different wiring/pinout vs silver blade |
| GM Silver-blade throttle body | varies | '05 P59 Silverado and similar | about $50-150 used | junkyards, dealers | Used/new Match to PCM calibration |
| GM TrailBlazer SS throttle body | varies | LS2/GTO-style blade, truck form factor | about $50-120 used | junkyards | Used market Known clearance issues in some swaps |
Prices are approximate as of September 2026. We list every option we know of, including small shops and used parts we can't link to. Confirm fitment with the seller.