I'd say go with the S4s. The S4s have 266 degrees duration and a whopping 11.8mm of lift and they are compatible with stock valve springs.

The HKS 264 Step 1s have 264 degrees duration and only 10.0/10.5 mm of lift.

The greater lift of the JWT cams allows them to make excellent power throughout the power band.

Scott, just curious....what do you think of my copmarison of the HKS to the JWT cams? Why do you prefer the HKS cams?

Peace,