SANS 10047:2007 item 5.39.2.1: "If any engine is fitted that is not of standard make and type for that particuler vehicle, reject if, in the opinion of the examiner, the engine is excessively powerful for the vehicle in question."
Did some surfing and came up with this. Kinda makes you think twice about the mods on a car. Especially engine swops, which this sub-rule seems to target.
Really don't thinks its fair that it leaves the decision up to the examiner. That opens the door for corruption, especially given the investment made in the vehicle.
The vehicle may be "Road Worthy", but they can still refuse to grant you a roadworthy certificate :cursin: