This listing covers Alliant Power new high-pressure diesel fuel injector lines for the 2001–2004 GM 6.6L LB7 Duramax, Alliant part numbers AP63720, AP63721, AP63722 and AP63723. Alliant’s injector lines carry pressurized fuel through the diesel injection system to the injectors.

Features & Benefits

• New Alliant Power LB7 Duramax fuel injector lines (Alliant P/N AP63720–AP63723)
• Each Alliant number replaces a specific GM line: AP63720 = GM 97188720, AP63721 = GM 97188721, AP63722 = GM 97188722, AP63723 = GM 97188723
• Match the GM number of the line you are replacing to choose the right option
• Country of origin: USA (per Alliant Power)
• Backed by Alliant Power’s 24-month, unlimited-mileage warranty

Application

• Chevrolet Silverado 2500 HD / 3500 and GMC Sierra 2500 HD / 3500 (2001–2004)
• Chevrolet Kodiak C4500 / C5500 and GMC Topkick C4500 / C5500 (2003–2004)
• Alliant’s parts-catalog titles list AP63720 and AP63721 as 2001–2004, AP63722 as 2001–2003, and AP63723 as 2003–2004

Always verify fitment against your VIN, engine, and OE part number before ordering.

Cross-Reference / Replaces

• AP63720 — GM 97188720; Dorman 904-129; DIPACO DT660030
• AP63721 — GM 97188721; Dorman 904-128; DIPACO DT660031
• AP63722 — GM 97188722; Dorman 904-127; DIPACO DT660032
• AP63723 — GM 97188723; Dorman 904-126; DIPACO DT660033
• Alliant Power: AP63720, AP63721, AP63722, AP63723

Warranty: Alliant Power’s standard warranty: 24 months with unlimited miles/hours on installed parts (Alliant Power warranty policy, rev. Aug 2025).