Automatic Transmission Shift Kits

Instead of replacing your automatic transmission’s whole valve body, you can get better performance out of your stock valve body with a transmission shift kit....

Instead of replacing your automatic transmission’s whole valve body, you can get better performance out of your stock valve body with a transmission shift kit. Different manufacturers use different components and techniques, but they all modify the way transmission fluid is routed through the valve body. Some kits are made for racing and performance driving, while others are for towing and heavy-duty hauling. Whatever your application demands, Summit Racing Equipment has the shift kit you need.

Top Brands

When it comes to the complexities of your automatic valve body, you want a manufacturer you can trust. Summit...

Top Brands

When it comes to the complexities of your automatic valve body, you want a manufacturer you can trust. Summit only carries transmission shift kits from top name brands, including TransGo, TCI Auto, B&M, Sonnax, and Performance Automatic.

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Sonnax Zip Kits 8L45-8L90-TCC-ZIP

Automatic Transmission Shift Kits, TCC Zip Kit, with O-Ring End Plugs, Converter Limit Valve, Regulator/Shuttle, Cadillac, Chevy, GMC, 8L45, 8L90, Kit

Part Number: SOX-8L458L90TCCZ

Not Yet Reviewed

Estimated Ship Date: Monday 3/16/2026 if shipped by air