Surtees did not include the overshifting limiter bits with the Quaife kit I bought for the 1360 motor.
Right off the bat it had problems with overshifting so I read through some old MPHs to see if anyone else had experienced this problem. Some had and there was mention of 2 small pieces used to prevent the overshifting. Some clever Vincent owner figured out what was going wrong and made the pieces to correct the problem. Quaife then started including those pieces in the kit ( except mine!). I made the pieces as described and that solved the problem. I also contacted Surtees Sport Power who agreed to send the same pieces. Those are sitting in a drawer somewhere as spares.
With that fixed, the shifting is perfect, it's never missed a shift even with near instant shifting at 6500 rpm.
With the stock four speeds on the Rapides I still miss sometimes, especially 1st to 2nd if a bit excited and trying to shift too fast at high rpm. High rpm in this case is not that high, maybe 4500-5000 rpm.