Which goes along with the aluminum "tube spacers" you reported on in your other thread.
So it seems you have a 78 triple tree and a 78 wheel and disk with 73 to 76 tubes and lowers Hate to ask this but what does the caliper look like? Is it finned and black with 1 piston (78)? or roundish looking with two pistons (72-76)? You really will need to change things to match. the wheel will work with either type fork. If you have the 78 Caliper then going to 78 to 83 tubes is probably the simplest and best way to go. The parts are readily available and not that expensive. The 78 tubes being bigger are stiffer and that is better especially if you want to keep extended tubes. Finally you need to get to the bottom of why the wrong tubes are in there. Were the original tubes bent in an accident? If so you need to check to see if the triples are straight, wouldn't hurt to mount the wheel and spin it to be sure it's not bent either.