What should I expect when upgrading to the GM 90mm (LS7) throttle body on a Silverado?

Here is what the documentation says. Each point links to its source; details depend on your exact computer, harness and transmission.

• LS2, LS3, LS7; 2007-2013: Gen IV four-bolt intakes (2007-2013 trucks, LS2, LS3, LS7) have no factory cable-throttle counterpart; GM never made a drive-by-cable LS throttle body with the four-bolt mounting pattern. (LSX Magazine (Power Automedia))
• E38, E67; 2007-2013: Starting in 2007, 58x systems use the E38 or E67 ECM; the 2007+ truck throttle body is 87 mm and the passenger-car LS3-style body is 90 mm, both with the same four-bolt pattern and six-pin connector, but their internal electronics differ and they are not interchangeable. (LSX Magazine (Power Automedia))
• E67; LS9, LSA; 2009-2015: Factory-supercharged LS9 (C6 ZR1 Corvette) and LSA (ZL1 Camaro, CTS-V) applications are all controlled by the E67 ECM, which is recommended for boosted-engine swaps; the E38 has two harness connectors and the E67 has three, and the E40/E38/E67 units are stamped between the fins and on the body label. (LSX Magazine (Power Automedia))
• E38, E67; LS7; 2006-2013: GM LS7 throttle body 12570711 is a four-bolt DBW unit for 2006-2013 Corvette LS7/Z06; it uses a nine-wire harness plug. (Speedway Motors)
• E38, E67; LS7; 2006-2013: The GM LS7 throttle body (12570711) is a four-bolt DBW unit with a nine-wire harness plug for 2006-2013 LS7/Z06 Corvettes; it belongs to the 58x Gen IV electronics family (E38/E67) and cannot be paired with a Gen III 24x controller. (Speedway Motors)

Confirm against the instructions for your exact parts before wiring. More: Throttle (drive-by-wire) in our tuning guide.