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LT1 LT4 coolant housing AN conversion with text on using -20 AN fittings
Close-up of a GM LT engine with a green circle highlighting a LT swap coolant plumbing -16 AN.
GM LT engine thermostat housing upgrade on a white background
Close-up of a car engine with visible billet LT thermostat housing for custom build.
&
LT1 LT4 coolant housing AN conversion with text on using -20 AN fittings
Close-up of a GM LT engine with a green circle highlighting a LT swap coolant plumbing -16 AN.
GM LT engine thermostat housing upgrade on a white background
Close-up of a car engine with visible billet LT thermostat housing for custom build.

'-16 AN Thermostat Housing for GM LT Engines

SKU: WA01000LT

$79.99
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Wide Open Design’s -16 LT Thermostat Housing is precision-crafted from 6061 billet aluminum and machined to exact tolerances for a clean, reliable solution when plumbing your LT-based build. Designed to simplify custom coolant routing, this housing allows you to run -16 AN hose and fittings while retaining your factory thermostat.

Included Items:

  • (1) -16 LT Thermostat Housing
    Note: Thermostat and AN fittings sold separately.
Specifications
  • Hose Size: -16 AN
  • Material: 6061 Billet Aluminum
  • Thermostat Compatibility: Factory LT Thermostat
  • Application: GM LT-based engines
  • Manufacturing: Precision Machined in the USA

Key Features

  • 6061 Billet Aluminum Construction: Exceptional strength, corrosion resistance, and long term durability.
  • Precision Machined: Manufactured to tight tolerances for proper sealing and reliable fitment.
  • -16 AN Outlet: Simplifies coolant plumbing with secure AN connections. No more hunting for molded rubber hoses.
  • Factory Thermostat Compatible: Retains OEM thermostat functionality to maintain proper ECU-controlled operating temperature.
  • Engine Bay Upgrade: Clean AN plumbing enhances appearance while improving serviceability.
Fitment

Designed for GM LT-based engines, including:

  • LT1
  • LT4
  • LT5
  • Other Gen V LT platforms
  • LT engine swaps
  • Tube chassis builds

Note: Always verify your thermostat style and coolant routing configuration before installation.

Tech Insight

Switching to -16 AN plumbing removes the guesswork from hose selection while delivering a more durable and service friendly cooling system. Modern LT engines rely heavily on accurate coolant temperature readings for fuel mapping, timing control, and emissions performance. Retaining the factory thermostat ensures:

  • Proper warm up cycles
  • Stable operating temperatures
  • Consistent ECU data
  • Reliable drivability

Works well with