Fortpro Piston Ring Set .020 in/.50mm Size for Cummins 4B 3.9 / 6B 5.9 Engines is the ideal solution for restoring the performance of engines that require reground cylinders. This set of oversize rings provides a precise fit that ensures a perfect seal and optimal compression, returning your engine to its original efficiency and power. Made from durable, wear-resistant materials, these rings ensure long-lasting, reliable operation. Compatible with OEM part numbers 3802232 and 505081, they are perfect for applications that demand quality and precision.








