Rebuilding a head on a 262 Buda diesel. It's a turbo motor out of a D-19.  How important is the rotaters ( valve spring retainer)  that go on the exhaust valves.  My rotaters are all junk with flat spots on all the balls.  So it is obvious that they have not been doing thier job as rotaters for a long.......... time.  I have an old style 262 diesel head that has valve spring retainers that are not rotater style.  Any thoughts on using the old style retainers on the new style head?   I realize the springs are different lengths and that i would have to use the coresponding spring for the non rotater style valve spring retainer. 

Thanks for the feedback.