The optimum ratio for the L36 was found by www.easyperformance.com
to be somewhere around a split ratio of 1.8 and 1.85. (The ER ratio)
ZZP had this ratio a while back and is soposedly going to have it back in stock. The only thing you'll need besides the rockers are new torque to yeild rocker arm bolts and valve cover gaskets.
The lift on these isn't high enough to see valve float. And IIRC people have ran these on stock springs with more mileage.
Definitely need a good torque wrench as was said.
And you'll defintely feel the difference.