408 Magnum stroker HEAD HELP!

I’ve never done it but probably should try it sometime is take a bare set of Speedmaster heads and open the pinch up to 1.0-1.010 and give the intake side a nice 70-60-45-30-15 valve job for a 2.055 valve.
I asked about getting bare SM heads from the guys here in calgary and they said no complete only ..... maybe a canada issue or just that parts store ?