ARP 900-0550 4.005 Bore Ring Compressor | 2001-2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax

Features: - Fits 4.005 inch bore applications - CNC-machined from 6061-T6 billet aluminum - True radius design for optimal ring compression - Bottom relief for wire O-ring clearance - Type 3 anodized for added durability - Used by professional engine builders worldwide - Engraved size markings for quick identification - Ensures smooth and damage-free piston installation - Reliable fit for consistent engine assembly results - Resistant to wear from repeated shop use - Precision tool for high-performance engine builds - Backed by ARP's trusted manufacturing standards Skip The Frustration And Get The Job Done Right Anyone who’s built a motor knows the ring install can be one of the most annoying steps if you don’t have the right tool. The ARP 900-0550 4.005 Bore Ring Compressor is made to take that pain out of the process and give you a tool you can count on every time. Whether you’re rebuilding a 6.6L Duramax or putting together a performance engine for the track, this compressor makes getting your pistons seated fast, clean, and frustration-free. It’s one of those shop tools that just feels right in your hands, solid, smooth, and engineered for results. The fit is spot-on, helping eliminate guesswork and prevent damage to your rings or cylinder walls. You’ll appreciate how clearly the bore size is marked and how easily the piston slides through without resistance. If you’re after a cleaner build and more control from start to finish, this is the kind of tool that earns its place in your top drawer. Built For Precision In The Tightest Tolerances The ARP 900-0550 ring compressor is purpose-built for those who demand pinpoint accuracy when assembling performance engines. Machined from 6061-T6 billet aluminum, it offers the strength and stability needed for consistent results during high-compression piston installs. The 4.005 inch bore size is cut to a true radius, not tapered, ensuring even pressure all the way around the ring pack for damage-free compression. This is especially important when working with tight ring gaps or custom ring stacks that require careful handling. The tool’s bottom edge is relieved to allow clearance for wire O-rings, giving the piston a clean path during installation into the cylinder. Its hard Type 3 anodized finish not only resists wear and corrosion but ensures a longer service life through repeated use. The oversized engraved markings make it easy to identify the right size in a busy engine bay or tool chest. For professional builders and serious DIYers, this compressor delivers the accuracy and quality ARP is known for. Fits: 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax Notes: - Designed specifically for 4.005 inch bore engines - Compatible with 2001-2016 GM 6.6L Duramax applications - Features a true radius bore for better compression - Not compatible with tapered-style ring compressors - CNC-machined from high-strength 6061-T6 billet aluminum - Bottom relieved for wire O-ring clearance during installation - Type 3 hard anodized for extended tool life - Engraved with large 3/4 inch bore size markings - Widely used and trusted by professional engine builders - ARP products are not returnable once packaging is opened