Used on extremely modified high HP high revving 196cc-225cc For small block honda clone engines For Tillotson 225. This is for a set of dual valve springs (a total of 4 separate springs). Approximately 50lbs at .880" and 55lbs at .850" installed height. These valve springs are designed to provide a higher spring rate than standard valve springs, which helps to prevent valve float even at extremely high RPMs. The dual spring design provides additional support and helps to maintain consistent valve timing and lift, improving engine performance. These valve springs are made from high-quality materials that are strong and durable, ensuring long-lasting performance. Stainless steel valves and billet or titanium retainers are required. Valve spring pockets may need to be modified.