Thanks so much fellas but I've had a change of direction. I'm now going to use PVL ignition. It's been a 16 years since I modified the IT ignition for my DT1 racer and I'd forgotten the amount of welding and machining needed to fit it. Since I've retired I haven't got the machining facilities I had at my disposal back then. Also, PVL is far more modern, more reliable and bolts straight on.