Which Kohler magnum are you referring to? If you are using stock valves rotator/retainer cups, springs it shouldn't matter they will not coil bind. If you are changing any of the above geometry. Once you have them installed with the cam and lifters set to zero lash, check the seat pressure first before setting lifters to zero lash, if OK then set to zero lash run the cam up on top of the lobe and check to make sure the springs do not coil bind. also check retainer to guide clearance. If all looks good I would say that you have all your poop in a group! LOL