Originally Posted by tech@WS6store

Lift isnt the only part to consider how aggressive a lobe is. The higher rate spring would be better for higher rpms or more aggressive lobes but have a 1.080 coil bind so arent rated for as much lift roughly .650. It will depend on the rocker arm used and weight over valve as to whether or not youd want to jump up to the higher rate.

Originally Posted by tech@WS6store

They will work with tfs heads yes. Those should be fine for the t001 heads if youre not going above 6500. if so the t002 heads would be better.

Originally Posted by tech@WS6store

Id recommend the t002 then based off that. Plus you are already closer on the lift vs shimming so you wouldn't have to worry about spring bounce etc from not having the springs installed at the proper height.