Hi Dahaya,
in my opinion you may have to think twice if you are planing to go for a diesel converted hi ace.i don't trust diesel conversions much.only thing that i know about 5L Toyota engine is,its a bit thirsty compared to the 3L engine.I had a toyota hiace LH113 model for more than 10 years with a 3L engine and it was fantastic motor i've always loved with better power.Hope this would help you.....