The theory as I understand it with these engines is that they could be run flat out all day which was 4.5k(they fitted a rev limiting rotor arm that cut out at 4.5k on some vehicles). I guess it comes down to what you are comfortable with taking into account noise, overtaking vehicles, engine...
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Haveacamper on here bought his import from FBIVW. There's a couple on there for 6k or less that you should be able to get up and running for less than 8k.
Edit: There are a number of other importers out...
Have a look at Haveacampers gallery thread on here, start at the beginning when he bought a 72 Dormobile.
It's an excellent example of a bus that looked alright when he bought it. Then have a look at what he bought to replace it after realising how bad the original purchase was(you can hide all...
Also looks like the Dormobile roof isn't original, Looks too far back which isn't necessarily a problem, depends on how they cut the roof to fit it, Dormobile weren't exactly careful with their roof mods either!!
Difficult to tell from the description and pics as there's not enough detail but if the rear end is knackered then id suspect a whole load of other rust related issues underneath. Some of the lower parts of the panels don't look very straight either.
For the amount it's going for now plus your...
Aren't the balljoints installed the other way up on transporterhaus trailing arms? And therefore the spindles are machined to accept them?
Who told you they would fit?
What exactly did the guy say was wrong with it?
What exactly were the symptoms? Loss of power? What sort of noises?
What were your pressure and temp readings?
Not sure you've really established there's anything wrong yet....