Jon, I think for the 3.0 tyres with speed index V will be fine. But for the 3.7 we need W-index tyres - I wonder if they are on the market.
There appear to be choices in W with Yokohama, Toyo, Michelin
I currently have a 3.7 and having done a couple of track days I'd be happy with V, as a trad Morgan gets quite 'floaty' at the front when your well over 120 - 130, the brakes are also marginal and get so hot that the excess kingpin grease smokes alarmingly when you return to the pits
So I'll be quite happy with V for road use legal speeds
