Watch out on this one. I just finished with this damn headache. Your retainers and keepers need top be matched up and some of the retainers have the wrong angles for the keepers! TA went through the trouble of remachining the retainers to get a proper fit. ...BUT... That's only 50% of the battle! Keepers then must be a good tight fit, no wobble or rocking, ideally with the same hieghts. I ordered keepers from 3 different vendors and all 3 sets were stamped, not machined. Stamped pieces do NOT fit properly in the retainers and will create severe stress risers that will easily crack a keeper at high RPM. Cracked keeper = valve dropping into cylinder! Pick up a machined set of keepers, or re-use the stock ones. Sizably better than the stamped ones IMHO.
