Sounds like the road tester was just anti-japanese vehicles , i feel i must defend the old Hi-Ace, as an ex-mechanic of over 18 years ,i have worked on dozens of Hi-Ace vans and never felt they were difficult to work on, in fact once you remove the drivers and passengers seat mounting plates ( ten 12mm bolts each side ) you have more access space that some bonnet style vehicles. I've even done engine out jobs on these vehicles, first remove the cylinder head from inside the vehicle, then drop the engine block out from underneath. Of coarse the number one reason to buy a Hi-Ace in the first place, is they don't go wrong very often ,so need very few repairs to the engine bay area ! ;D.
On that note, I'm interested in finding out more on engine options for the late 70's-early 90's hiace. (I'm thinking about a camper some time in the future.) I see some with a 1600cc 12R, which I know nothing about, and others with 2000cc 18R, which I know about from my Celica. Is it easy to swap these engines, or even use a 2.2 or 2.4 diesel?