Stage 1 - $1,695
Upgrade to suit bolt on parts, 550-750hp engines. Must have valve spring upgrade.
258-A: 264/268 Degrees advertised duration. 9.50mm/10.40mm lift.
Stage 2 -$1,695
Suited for built engines running 850-1000hp. Great with aftermarket plenums. Can run using full Valvetronic system or locked in full open position when using an aftermarket throttle body. Must use KVS58-BT spring kit.
258-B: 285/280 Degrees advertised duration. 9.65mm/10.60mm lift.
Stage 3 - $1,695
1200hp+. Great when using alcohol based fuels and big boost. Recommended locking the Valvetronic system at 100% swing, must use aftermarket intake plenum with single throttle. Suited to professional built engines. Must use KVS58-BT spring kit.
258-C: 288/288 Degrees advertised duration. 9.65mm/10.80mm lift.