Valve Spring Recommendation

Currently installing Mopar Performance Purple Shaft P4452757AE in my 273.
Lift Intake: 0.410 Exhaust: 0.425
Adv Dur: 248/256
Dur @ 0.050: 211/218
Edelbrock RPM Perf Heads
I am having difficulty finding the correct valve springs. Any recommendations? Thx, 65