Millennium Technologies specializes in cylinder repair and maintenance services for a wide range of vehicles, including automotive cylinders, crankshafts, and cylinder heads. They offer services such as engine rebuilds, head repairs, stock bore kits, performance big bore kits, and crankshaft balancing. Additionally, Millennium Technologies provides services like 2-stroke and 4-stroke porting, isotropic micro polishing, and dyno tuning. They also offer products such as American V-Twin bolt-on big bore kits, monster big bore kits, and service big bore kits. The company prides itself on quick turnaround times and offers a cylinder core exchange program to eliminate downtime for customers.