Very little, powerglide finally changed due to fluid leaks, cast iron 186 engine very smooth and reliable, driveshaft vibration due to wrongly installed uni joints on it.
Original premier vynil roof still good after 35 years, car has lots of personality, light steering, soft ride with no jarring on the roughest roads, very good visibility, all 4 corners can be seen by driver, a huge amount of headroom and legroom compared to modern cars, also a very big boot.
Suspension fixed with stabiliser bars has disc brakes, regularly treated with fish oil spray for rust. Modern cars are far too unreliable and complicated.
Giday mate,sounds like a good old reliable holden arnt they all. i have 2 hours, one is a 1966 ute 208 stroker and the other is a sedan in the process of being restored, over the years I've owned 5 hours and to me there is no comparison to any other holdens. i love the shape and the model, i will never get rid of my hours they r getting harder to get these days.