Jonny-Jimbo

No noticeable difference from changing to twin carbs on such a small engine. An engine is designed to 'work' with what the factory fit it with, whilst this isn't always the most powerful set up of the engine, it's one that works. Changing only the carbs will result in over fueling, and changing the carbs and exhaust will result in a very marginal gain in power, but probably not noticeable. You'll think you're going faster because of the noisier exhaust and induction noise.

Just a side thought; as the tie-rods are longer on the Vitesse, on both Rotoflex and swing-spring cars, does that mean you're more likely to get tuck-under due to the longer swing angle available from a longer tie-rod?

Raider, I thought satnavs etc weren't meant to be used on RBRR?