Thank you both,
I am helping a friend to build his motor similar to mine.
the Yella Terra 6015 are only available in Australia: AU$ 924,- = €580,-
the Scorpion 3224 in the US: $ 680,- = € 615,-
all without shipping and tax. Too expensive, guess we use the standard rocker arms or go with stud mounted, knowing about the limitations.
I bought my Ford Racing ones for $ 320,- = € 250,- in 2013 ... what at bargain.
Merry Christmas and a Happy New Year to all of you,
Ulli