I found a speed limit sign on the road (street view link) that shows 80 km/h northbound out of Burgeo. There is another one near the junction with the Trans-Canada Highway the other way (street view link). So it seems likely the speed limit on the majority of 480 is 80 km/h.
There’s a “moose” sign a little further on, which probably means you want to be careful in any case.
Credit:stackoverflow.com‘