LS Swap Guide: Learn the Differences Between LS Water Pumps

FIND OUT WHICH WATER PUMP WILL WORK BEST FOR YOUR LS SWAP

No two water pumps are made exactly the same, and when it comes to making sure your LS swap goes off without a hitch, it’s important to know just which water pump you should choose. While there are water pumps designed for your specific car, truck, or SUV, that doesn’t mean that choice is always the best for your configuration.

In this blog, we’re going to discuss the different types of LS water pumps you can buy. Make sure to stick around until the very end because we’re sharing a versatile way to swap out your water pump and have it work for any configuration you have planned now or in the future!

SEE ALSO: ICT BILLET LS SWAP GUIDE FOR GEN III & GEN IV

How To Determine Which LS Water Pump You Need

One of the most important steps of any LS swap is determining the ‘offset’ you’ll need for a proper placement and fit. At ICT Billet, we have made this an easy process. Once you know your offset, finding the LS water pump for your swap becomes a breeze.

Ultimately, your offset (also referred to as ‘spacing’) is determined by the crank pulley that you either currently have or will be getting. When it comes to locating the right parts and accessories, this offset categorization we’ve developed will help ensure that the kits you receive from ICT Billet will directly bolt up to your application and provide proper functionality.

In order to determine which water pump you need for your LS swap project, you’ll want to refer to the list below featuring the three offset categories we design all our brackets off of.

-1 (DASH ONE) SPACING

Swap vehicles that fall under our -1 offset category include Corvettes, CTS-Vs, SS sedans, and G8s set up with these engines:

• LS1 Corvette
• LS2 Corvette
• LS3 Corvette
• LS9 Corvette
• LS7
• LSA

-2 (DASH TWO) SPACING

Swap vehicles that fall under our -2 offset category include 1998-2002 Camaros and GTOs set up with this engine:

• LS1 Camaro
• LS1 & LS2 GTO

-3 (DASH THREE) SPACING

Swap vehicles that fall under our -3 offset category include all trucks and 2010-2015 Camaros set up with these engines:

• Gen III Truck
• Gen IV Truck
• LS3/L99 Camaro

Here’s a great visual guide to determine spacing/offset for swapping out your water pump based on ICT Billet’s bracket design:

LS Water Pumps for -1 Offset

All together, there are seven different common types of water pumps available for LS swaps. Of the eight available, four are for vehicles with engines that have our -1 offset configurations. LS1 and LS2 pumps are nearly identical. They both have water outlets on the upper passenger side. However, an LS2 pulley is smaller in depth and their thermostats are not the same. Also, the LS1 pump provides a better seal and larger bearings.

Additional notes for LS1 pumps: Corvette and Camaro use the same pump since the pulley is very wide (unlike any of the other water pumps), so it can accommodate -1 and -2 belt spacings

Additional notes for LS2 pumps: LS2 pumps are available in -1 Corvette (this pump is its own casting, not used on other models), -2 GTO (exact same as LS1 Camaro), and -3 Trailblazer (exact same as Truck Gen IV)

When it comes to water pumps for LS3, LS7, LS9 and LSA swaps with -1 offsets, the main differences lie in the water outlet location and pulley depth. Water pumps for these engines house the water outlet on the upper driver’s side rather than the passenger side like the LS1 and LS2 pumps.

If you’re working on an LS swap project and need to swap out your water pump to fit your new engine, you’ll know your crank pulley has a -1 offset (also known as -1 spacing) if it fits any of the engines listed below, which will help you determine which LS water pump you need:

• LS1 Corvette
• LS2 Corvette
• LS3 Corvette (you’ll also want to use this pump for LS7 and LSA engines)
• LS9 Corvette

LS Water Pumps for -2 Offset

Only three types of engines fall into our -2 spacing category when it comes to crank pulleys, and ultimately, your water pump. Those are engines for:

• LS1 Camaro
• LS1 & LS2 GTO
• LS1 Firebird

Just like with our previous water pumps listed above, the water pumps that fit engines in this category differ from others available due to their own unique pulley offset. LS water pumps for LS1 Camaros, GTOs, and Firebirds also house the water outlet on the upper passenger side, similar to that of the LS1 & LS2 Corvette water pumps, but the crank pulley offset itself is wider, requiring the water pump brackets to allow for this difference in offset.

 Here’s a visual to explain how the spacing of your crank pulley affects the offset for your water pump:

LS Water Pumps for -3 Offset

Last, but certainly not least, we have water pumps for Gen 3 and Gen 4 LS truck and LS3 Camaro engines. Truck engines themselves have a unique setup when it comes to the water pump’s water outlet location as they sit vertically on top of the pump. This can pose unique challenges in some applications, but we’ll discuss that more in the next section. For now, it’s important to know that while you can use certain water pumps for LS car engines in truck engine applications, you cannot use a truck engine water pump in an LS car engine configuration.

Truck engines aren’t the only ones in this category, though. We also have the LS3 Camaro that features a pulley much smaller in depth than others listed previously due to the crank pulley offset. The LS3 Camaro water pump also features the water outlet on the upper driver’s side.

Don’t forget, when it comes to finding the right water pump for an LS engine with a -3 offset, you’ll want to look for those that fit the following:

• Gen III Truck
• Gen IV Truck
• LS3 Camaro

The Absolute Best LS Water Pump with the Most Versatility

When it comes to choosing the best LS water pump for your swap, versatility and adaptability are key. Most car enthusiasts agree that even if this is your first swap, it most likely won’t be your last, and if you change your LS engine down the road for one with a different offset, wouldn’t it be ideal to not have to also buy a new water pump?

LS1 water pumps are the most common and universal water pump for swap projects you can find. This is because of the lower water outlet port and the deeper pulley. An LS1 water pump is the absolute best, most versatile, and user-friendly water pump for multiple pulley offsets. Because of its versatility, you can use the LS1 water pump with literally any configuration, which makes it perfect for both current and future projects.

LS1 WATER PUMPS AND LS TRUCK ENGINES

It’s important to note that if you’re using an LS1 water pump on a -3 offset, you’ll need one of our water pump spacers. You can use LS1 water pumps for truck engines, but a water pump designed to fit a truck engine is not used on an LS1 due to water outlet height and pulley offset.

So why would you want to use an LS1 water pump on a truck engine at all?

In some applications, the truck water pump outlet is too high, which creates air pockets and doesn’t allow your coolant to flow properly. To avoid this potential issue, you can simply install an LS1 water pump with the spacer and have a format that is easy to install and avoids potential drawbacks. LS1 water pumps can be used as a direct bolt-on for -1 and -2 offset configurations, without requiring the additional spacer.

If you're short on funds but still want a viable solution, another option would be to purchase the water pump spacers you need from ICT Billet to make your current water pump work for your application. If you decide to go this route, just make sure to keep in mind things like where your heater hose will run into the water pump, which intake manifold you’re using, what ICT Billet brackets you’ll use, and so on. Check out the water pump spacers we offer.

Ready to find the LS swap parts and accessories you’re looking for? We’re proud to provide you with all American-made products, built from premium materials, and priced affordably so that you can make your next build the best it can be. Need help figuring out what would work best for your setup? We’re happy to help! Simply give us a call at 316-300-0833 or fill out our online contact form and one of our team members will respond shortly.