Whilst a twin cam head idea from scratch is a fantastic idea, people have been trying for years to come up with a cost effective alternative. And that is the whole point. It has to be cost effective. Because while the real serious boys might consider spending $10K on a head, the rest of the Datsun community will not. The best way to make something that is cost effective is to use parts that are easily sourced so the only thing that is really custom is the head itself, not all the gear that goes on it. Then you might be pleasantly suprised. The biggest thing is the pattern work, which I have stated before, because machining a head from billet would cost a crapload and would most likely be done in 2 pieces. I for one would love to see one, but I am yet to see one running, and some seriously smart blokes have tried and failed, because it cannot be done cheap, or without consuming huge amounts of time along with the huge influx of cash. Why would you? When so many aftermarket alternatives are at your feet anyway.