cam and spring ?

ok my la 360 with mag. heads the cam just went up for the second time so im thikin about scrapin the summit pice of **** and goin with a hotter cam mopar performance 484 lift but with the magnum heads they got 1.6 racio rocker arms i need springs that are around 518 lift with magum heads
so if anyone knows about springs for magum heads that are cheep dont got much money thanks
tom