CXRACING Trans Oil Cooler for Silverado 1500/2500/3500HD 6.6L Duramax Diesel V8 CXRacing Transmission Oil Cooler Upgrade Kit For 2000-2004 GM Chevrolet Silverado 1500HD/2500HD/3500HD with 6.6L Duramax Diesel V8 Large 30 Row High Performance Oil Cooler, Replaces Smaller Stock Cooler Fits Stock Oil Cooler Lines and Fittings. Comes with Mounting Brackets, Bolt On Fitment This Oil Cooler Kit ONLY Fits 2000-Early 2004 Model with 5 Speed Automatic Transmission, Which Has NPT 1/2" Fitting. Late 2004 and Up Model Has Larger Oil Cooler Fitting, Does NOT Fit This Kit. Please MAKE SURE You Check Your Stock Fitting Size Before Buying.