Life time Warranty
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  • 100-percent aluminum construction provides greater heat and pressure tolerance, better heat dissipation, increased durability, improved cooling efficiency, and improved structural rigidity
  • 3-row core
  • Increased coolant capacity directly results in better cooling efficiency and reduced engine temperatures
  • Includes an internal transmission cooler to provide optimal fluid temperatures for automatic transmissions
  • Billet aluminum fill neck
  • Brazed aluminum core with TIG-welded end tanks
  • Includes magnetic drain plug
  • Mishimoto Lifetime Warranty


If you're looking to upgrade your GM 3100 Series parts, look no further! The Mishimoto 1955–1959 GM 3100 Series Truck X-Line Performance Aluminum Radiator provides your truck with enhanced reliability, improved cooling efficiency, and is an ideal upgrade for the brittle stock radiator. Whether you use your classic for daily driving or take it to the track, many people overlook the importance of installing an upgraded radiator in their engine. A stock radiator cannot handle the heat that comes along with having a great deal of horsepower.The Mishimoto GM 3100 Series Truck X-Line Aluminum Radiator is manufactured using durable aircraft-quality aluminum end tanks, precision TIG-welded to an efficient brazed aluminum core. The inlet and outlet provide precise leak-free connections. This GM 3100 Series performance radiator also includes a Magnetic Oil Drain Plug, which effectively removes metal fragments circulating in the cooling system. As with all our aluminum radiators, this GM 3100 Series radiator includes the Mishimoto Lifetime Warranty, ensuring superior product quality and craftsmanship.

Purchase Includes

Mishimoto Radiator--Mishimoto Radiator Cap--Magnetic Drain Plug--Mishimoto Lifetime Warranty


Transmission Cooler Thread Info:--On Radiator: Female 1/4-inch BSPP--Sealing Face: 70
More Information
Overall Height (in)27
Overall Length (in)26.2
Overall Width (in)5.6
Core Length (in)21.7
Core Height (in)19.4
Fluid Capacity (gal)4.96
Inlet (in)1.5
Outlet (in)1.75
Core Thickness (in)2
Drain Plug Thread SizeM12 x 1.5
Applications1955-1959 GM 3100 Series Truck
Engine Codes235ci (3.9L) I6--265ci (4.3L) V8--283ci (4.6L) V8
NoteTransmission Cooler Thread Info:--On Radiator: Female 1/4-inch BSPP--Sealing Face: 70
Coolant Capacity4.96

Mishimoto Automotive (“Mishimoto”) warrants its products under this lifetime limited warranty policy (“Warranty Policy”). This Warranty Policy applies solely to: (i) Mishimoto Products purchased directly from Mishimoto or Mishimoto authorized dealers (each a “Mishimoto Product” and collectively, the “Mishimoto Products”) and (ii) the original purchaser of such Mishimoto Product (“Purchaser”). This Warranty Policy is non-transferable and all claims under this Warranty Policy must be accompanied by the original sales receipt. The terms and conditions of this Warranty Policy are subject to change by Mishimoto at any time without notice.

For our complete warranty policy, please click here.