[Malcolm]

"Do you have an opinion as to the effect of shortening the A-arms by 40mm? "

This is what Andrew has done and by his times this year he appears not to have suffered at all.

With regard to the speedo sensor, why not just block up the gearbox casing hole and use an electronic speedo with a pick up sensor working off the cv joint. Or even use one off the front wheels. This is where I have one for my telemetry sensor. Has the added benefit of being programmable to allow for different radius tyres as you chop and change through the life of the car.

Malcolm