My father had petrol cars (no choice after the war and had a petrol Morris with over 400,000 on the clock before the MOT did it in.) and diesels on his farm. All the farm stuff, tractors etc, were diesel for reliability and red diesel fuel cost! Most I had to maintain. No problem with that and after dad had a diesel Volvo 240- the most noisey smelly unreliabe turbo/diesel 6 cylinder we ever had. I got into using the series one Land Rover we also had, fantastic fun!
Yes I agree a well Looked after diesel should go forever. But a P38 diesel is, in my opinion, underpowered in that car. As you say a well looked after........ whatever p38 should provide a reliable car. This chap is looking for a petrol car he can convert to LPG so he (unless you can convince him to go diesel = and why not) needs to find ideally a V8 converted to top hat liners (Think Mozz Smith is selling his?? 4.6 2001 v8) or a well maintained low mileage Diesel with all history.
As it happens my V8 has the XM prefix to the engine number meaning it was manufactured by Mitchel Cotts a company who took over manufacture of the venerable V* from LR - see
Land Rover Owner • View topic - New replacement Range-Rover V8 engines; 'Original' design
so look for this frefix if purchasing a later V8
ps I am not silly - that was unessessary. I am just passing an opinion,