Need help buying a gq

[Brodie tas]

Hi i have a mates mate selling a petrol gq it has had quite a bit of offroad gear dual tanks 5inch lift bar work etc it has around 300000ks and the owner is ment to be pretty fussy with services, when i go have a look at it is there any common problems with these engines? Or signs to look out for just dont want anything thats going to have engine issues. Thanks for any help just dont know much about them