Swap Guides

LS Swap Guide (Gen 3 and 4)

LS Water Pump

LS Water Pump

LS Water Pump Compatibility & Differences

Choosing the right water pump for your LS swap is critical. Not all LS pumps are interchangeable — pulley offset, outlet location, and casting style vary by engine family. Use this guide and the ICT Billet links below to make the informed choice.

How to Determine Which Water Pump You Need

All ICT Billet brackets are based on three spacing (offset) categories, set by your crank pulley and accessory alignment.

Offset Typical Engines Example Vehicles
–1 (Corvette) LS1, LS2, LS3, LS7, LS9, LSA Corvette, CTS-V, G8, SS Sedan
–2 (F-Body / GTO) LS1 Camaro, LS1/LS2 GTO 1998–2002 Camaro, Firebird, GTO
–3 (Truck / LS3 Camaro) Gen 3 & Gen 4 Truck, LS3 / L99 Camaro Silverado, Sierra, 2010–2015 Camaro

LS Water Pumps by Offset

–1 (Corvette) Pumps

  • Outlet on upper passenger side (LS1 / LS2) or upper driver side (LS3 / LS7 / LS9 / LSA).
  • LS1 and LS2 are very similar; differences in pulley depth and thermostat type exist.
  • LS3 / LS7 / LS9 / LSA pumps share the same casting and outlet orientation.
  • Suitable when your crank pulley spacing is –1.
  • Example: LS1 Water Pump (WAT200)
  • Also: LS3 / LSA / LS7 (Corvette) Pump (WAT101)

–2 (F-Body / GTO) Pumps

  • Outlet on upper passenger side, similar to LS1 / LS2 style.
  • Deeper offset than –1 spacing.
  • Designed for LS1 Camaro, Firebird, and GTO style installations.

–3 (Truck / LS3 Camaro) Pumps

Using LS1 Water Pumps for Versatility

The LS1 water pump (WAT200) is the most flexible option. It works directly for –1 and –2 offsets, and with ICT Billet water pump spacers for –3 offsets so you have a better top radiator hose position for a cleaner look.

When installing on a truck engine, pair with the proper spacer kit to maintain alignment, avoid interference, and ensure proper coolant flow.

Important for VVT Engines (Variable Valve Timing)

If your LS engine uses VVT, your options are extremely limited. Only two water pumps will physically clear the VVT timing cover: the Gen 4 Truck pump (WAT301) and the LS3 / L99 Camaro pump (WAT302). All other water pumps will interfere with the timing cover, even if you use spacers.

Thermostat Housings

Thermostat housings are different between Gen 3 and Gen 4 LS engines because of the different bore diameter and seal depth in the water pump. ICT Billet makes adapters that allow the use of SBC-style thermostat housings, which provide many outlet directions, styles, and sizes.

We also make billet straight thermostat necks — 551836-LS1ST and 551836-LS3ST — and -AN versions in both -20AN (551836-LS120, 551836-LS320) and -16AN (551836-LS116, 551836-LS316).

This thermostat housing connects directly to the bottom of the radiator. All LS engines use a factory lower hose size of 1-1/2", and the upper hose connection on all LS pumps is always 1-3/8".

Remote Electric Water Pump Options

If you're running a remote-mounted electric water pump, ICT Billet makes several options to adapt your setup:

We even sell fittings to convert your factory hose barbs to -AN lines for cleaner routing. View compression fittings here.

Hardware and Gaskets

Don’t forget the hardware — we have everything to mount your LS water pump properly:

Need Help Matching Everything?

Use our LS swap tools or reach out to ICT Billet — we can help you select the correct bracket, pulley, and spacer combination for your specific build. Get it right the first time.

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