I've read from a few sources that the engine oil capacity for a 6G74 is 4.7L.

I filled up with 4.3L and it showed above max.

Is there a reason for this? Sump has no dents in it, and filter used was the full size Mitsubishi one, not the smaller Repco etc filters.

I guess that's level after the motor was run to fill the filter up?

Just go by the dipstick. The quoted capacity is for a DRY fill.

This has happened to me on 2 occasions also, had me buggered!

Just go by the dipstick. The quoted capacity is for a DRY fill.

this. don't forget that there's still oil throughout the engine after doing a drain. oil pump would still have some inside it, ready to coat everything on start.

did you start, then check oil level?
Empty filter takes a bit to fill ;)

Did you replace the oil filter?
After running it you will find it lower a little to fill the filter.

Yes oil filter was changed and I checked the level after running the motor

It is what it is then, never taken exact notice of the volume of oil I've used but more than 4L 4.5 is probably tops.

I generally have around .5L to .7L left over from a 5L bottle, think I put around 4.7L in once but it was slightly over full.
It probably just depends how long you let it drain for, I usually let it drain for a good 30-60 mins and run .5L through with the sump plug out to push more older oil out and allow it to drain more again.