If you are going to run one of the bigger cams, over 272 degree or the GSC 2, Kelford, HKS 3 or TMS Stage 2 or larger then you need the performance spring package to handle the lift and RPM. Please note that the dual valve spring versions do NOT fit the 1JZ head

Kit includes:

24x SPR-TS1015
24x RET-TS60/T1
24x SEAT-TS1015/2

SuperTech Valvetrain has proven worthy in a variety of motorsports applications, from mild 150 horsepower street engines to 1000+ Horsepower race cars. Don't be fooled by lesser quality valvetrain components! Stick with Supertech, and get the quality you deserve for your project that will fit right the first time and offer superior performance and longevity. In fact, some of us at SupraStore run their parts in our daily drivers...

Supertech Valve Springs are made with premium Superclean Chrome Silicone Vanadium Steel alloy for higher performance and durability at high RPM's, and better memory. They are also computer designed to ensure that wire stress levels do not overpass the limits of stress defined in the diagrams of fatigue for long durability under extreme conditions. Computer software also allows certainty to make sure that the harmonics are well under control.

The Supertech Retainers are manufacturer with high quality military certified Titanium alloy, and CNC machined for a tight fit that will ensure a long durability.

Spring Specifications:

Outer Spring -- 27.50mm OD -- 20.00mm ID
Inner Spring -- 20.00mm OD -- 15.20mm ID
12.90mm Max Net Lift
20.70mm Coil Bind
12.10 lbs/mm Rate