B-RB 3690933 spring what retainer?

Installing MP cam 4529270 They recommend Springs # P3690933 which I have. Stock BB heads with 3/8 stock valves, what retainer should I use? I have looked in all my books ETC. and the retainer numbers for this spring seem to be something that wont fit a stock valve? I know all the number in the books and none seem to fit the switch over. This cam change has likely been done a million times...so what retainer are you guys using? locks would stay 8Deg, or move up to 10? Relatively stock rebuild just a cam upgrade and springs to match....So..what have you used and what works?
Thanks!