If you go the straight axle route you'll need a bigger engine. The RGBs are there for a reason; a heavy bus needs lower gearing for the limited engine power. Personally I think lowered buses look stupid and are far less useful, especially in African conditions, but each to their own. Just consider that for the sake of looking "cool", you'll forfeit ground clearance, turning circle, load carrying ability and ride and handling quality. Not really ideal for a touring bus. I think most lowered buses are really only good for short posing drives in the city. But whatever floats your boat.
I drive stock split buses all over the country and they're designed to cruise all day at maximum speed. 100km/h cruising does no harm at all. Cruising at 3,000rpm means the fan is also turning slower, so cooling is not so effective. 3,500rpm is ideal crusing speed for a type1 engine.
When it comes to building engines, don't skimp. A properly rebuilt stock 1600 will set you back at least R8k. I had an 1835 with CW crank built a few years ago for about R18k, everything else stock. 1835s are not ideal bus engines as they have thin cylinder walls.
IMPI has built me a dual Weber 36IDF 1776 with CW crank, 100 cam, etc. I don't like to think what the total cost has been, but well over R20k, and that involved collecting all the parts over a number of years. We're fitting the engine to my 63 Dormobile next month and then we'll tally up the total cost and post on the forums to give people an idea of the true cost of building a mild performance engine.
Anyway, good luck with your build.
