2003-2007 Chevy/GMC 2500 3500 8.1L Allison 1000 High Performance 4 Row Radiator

2003-2007 Chevy/GMC 2500 3500 8.1L Allison 1000 High Performance 4 Row Radiator

Built for the 8.1L Vortec trucks running the Allison 1000, this radiator pairs a 4-row extruded tube core with an integrated transmission heat exchanger and engine oil heat exchanger, putting all three cooling circuits on one unit instead of scattering them across separate coolers competing for airflow behind the grille.

Extruded tube construction starts as a single piece of aluminum instead of a folded and seam-welded strip, which means no seam running the length of the tube to become a weak point under pressure or thermal cycling. Wall thickness stays consistent all the way around the tube, so the core holds up better to the constant pressure swings and heat load these trucks see under a heavy pull, and it shrugs off road debris and rock strikes that would puncture a thinner folded tube. That’s paired here with 5mm fin spacing for more fin surface area per inch — the difference that shows up when you’re towing in traffic, idling in a work site, or holding a grade at low speed where airflow across the core is already working against you.

The core is fully TIG-welded aluminum, natural finish, built to handle the heat these trucks generate when the 8.1L is under load and the Allison is working through gears at low road speed. Core measures 37.79″ W x 19.49″ H x 1.77″ thick, with an overall footprint of 44.4″ W x 23.5″ H x 6.3″ thick to fill the factory core support. Crossflow configuration routes coolant inlet upper driver’s side at 1.57″ to outlet lower passenger side at 1.83″, matching factory hose routing so there’s no re-plumbing the cooling system to make it fit.

Transmission cooler adapter fittings are included to mate up to the factory Allison lines, so the integrated trans heat exchanger connects without sourcing additional fittings. Direct fit for 2003-2007 Chevy/GMC 2500 and 3500 trucks equipped with the 8.1L Vortec and Allison 1000 transmission.