187 degree LS engine thermostat with gasket on a white background
LS thermostat for -16 AN housing with text on a white background
LS swap cooling system 187 degree thermostat with specifications on a white background
OEM replacement LS thermostat with seal bottom view on a white background
187 degree LS engine thermostat with gasket on a white background
LS thermostat for -16 AN housing with text on a white background
LS swap cooling system 187 degree thermostat with specifications on a white background
OEM replacement LS thermostat with seal bottom view on a white background

187° LS Engine Thermostat with Seal

45687

$28.69
/
Shipping calculated at checkout.

This 187 Degree LS Thermostat is the go to choice for LS builds and is designed to OEM specifications, manufactured with high quality materials, and built to withstand demanding cooling system conditions.

It’s the perfect match for our WA01000LS or WA01000LT -16 LS Thermostat Housing and WA01001LS or WA01001LT -20 LS Thermostat Housing.

Includes:

  • (1) 187° LS Thermostat
  • (1) Gasket / Seal
Specifications
  • Temperature Rating: 187° F (86° C)
  • Material: Copper & Stainless Steel
  • Flange Thickness:
    • 1/16 in
    • 1 mm
  • Flange Diameter:
    • 2-1/8 in
    • 37 mm
  • Bypass Flange Diameter: 37 mm
  • Height:
    • 2-9/16 in
    • 65 mm
  • Height Between Flanges: 1-13/16 in
  • Jiggle Pin / Air Relief Valve: Yes
  • Seal Included: Yes
  • Thermostat Included: Yes
Fitment

Designed for GM LS-based engines, including but not limited to:

  • LS1
  • LS2
  • LS3
  • LS6
  • LQ4 / LQ9
  • LM7 / 5.3L variants

Ideal for use with -16 and -20 AN LS thermostat housings.

Note: Always verify flange diameter and height measurements before installation in custom applications.

Tech Insight

A 187° thermostat is ideal for most LS performance builds. Constructed with a dual bridge stainless steel frame, copper casing, premium wax compound actuator, and integrated air relief valve (jiggle pin), it delivers:

  • Faster temperature response
  • Stable operating temperature control
  • Improved engine efficiency
  • Reduced warm-up time
  • Reliable sealing and durability

Whether you're plumbing a full custom LS swap or upgrading your cooling system, this thermostat provides consistent, predictable performance.

Back to Newest Products