Product Summary

Chevy Small Block V8, 2.75" Assembled Height, Steel

  • Beautifully chrome plated
  • Uses O-ring for a perfect seal
  • Strongly recommended for any performance application
  • Modified for high RPM/high flow applications, 180° temperature range

Comes as a Kit

Key Specs

MFG. Part #9100581
BrandSpeedway Motors
Material TypeSteel
Hardware IncludedYes

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Speedway Motors 9100581 Details

Thermostat Housing

These beautifully chrome plated water necks easily install in place of OEM water neck housing.  They use an O-ring for a perfect seal and are supplied with all necessary bolts and seals.  These water necks are designed to fit 1955-1965 Small Block Chevy V-8, stock 1964 Chevy II, and 1956-1963 stock Corvettes. They are angled 45 degrees and straight forward.

  • Chrome plated
  • Easily install in place of OEM
  • 45 degree angle, straight forward
  • O-ring for a perfect seal
  • O-ring and stainless steel bolts included
  • Fit: Small Block Chevy V-8:
    • 1955-1965
    • stock 1964 Chevy II
    • 1956-1963 stock Corvettes



Speedway takes a quality Robertshaw 330-180 high flow 180° thermostat, then modifies it to function properly in high RPM, high flow applications. They feature a balanced sleeve design and are strongly recommended for any performance application. Fits most domestic applications.

  • 2-1/8" diameter 
  • High flow 180° thermostat
  • Balanced sleeve design
  • Recommended for any performance application
  • Fits most domestic applications

Learn more about the importance of the thermostat with cooling systems and how they work by reading our tech article, Cooling System Principles.


Speedway Motors 9100581 Specifications

MFG. Part #9100581
BrandSpeedway Motors
Material TypeSteel
Hardware IncludedYes
Assembled Height2.75"
Base Height.37"
Hose ID1.50"
Angle50 degree
Tube Length1.67"
Tube I.D.1.27"
Centerline of Holes3.25"
Sold in QuantityKit
NotesIncludes O-Ring