I have a set of k-motions that are sold by Brodix and come on their assembled small block heads. My cam has almost the same lift as yours with 1.6 rockers. The springs are 1.55,installed at 1.950 and are 240 lbs on the seat and about 570 lbs at full lift. No clearance issues at all with the T&D rockers on Indy 360-2s. I have .780 seal to retainer clearance at full lift. Hope everything works out for ya Bill -Randy