Exellent find on the last Vizard article (I've had the first one for a long time). I've been trying to buy that from the states, they answered my first enquiry but did'nt bother when I asked how/where to send the payment. That may have answered a long standing question of mine, where did the 40/35 combo come from... good o'l Mr Vizard... though some idea's regarding inlet/exhaust flow ratio's have changed over the years. The race Crossflow (Ford Kent engine) R.E.C valves that Dave Walker used are still relevant, that's what mine are based on in my hotrod/hillclimb head. The Isky springs are "ok" to a point, but with the radical hotrod cam, they used to break all the time, though the owner did claim to use 9,500 regularly ! When John Read originally changed them to the Crane springs for the previous owner, the problem went away in his hands. I have since had to replace 1 spring in the early days of the engine, which is much better than all eight every half season that they used to go through ! I'll report back on this when I strip the engine in the next couple of months.