Aussie Ford Falcons of the AU series 4.0 litre use 2 valves per pot, and have 7mm stems. I think the intakes have a 47mm head (about 1.85")....???
The 'XR6' has 41mm (about 1.61") exhaust valves.
If you wish, I could compare them stem length wise versus Slant valves....???
