I can answer No.2 as I have a black head on my Genny, as for the rest, hopefully they will get back to us.
Mind you, there are two versions; a black version of the old red head and one with a larger center between the fins
so there is better access to the glow plug. I am not sure what reason for this is, maybe less cooling on the big hole one?
So I have revised the questions:


CEN Racing, can we please have the answers to the following questions?
1/. Are the Genesis, Nemesis, & GST blocks the same & therefore interchangable?
2/. What is the difference between the two different types of black GST Head?
3/. Are the Genesis, Nemesis, & GST piston, sleeve & crank interchangable? ( I realise that the GST has been developed / tuned differently)
4/. Finally, are the Genesis, Nemesis, & GST carbies different & if so are they physically interchangable?

Many thanks in advance for your answers to these questions.