Measuring the track is really easy by yourself. Grab your tape measure and push the end hard up against the inside of one tyre and measure to the equivalent point on the outside of the opposite tyre.
its the length from the oustide of the disc - ie where the wheel bolts on, to the same on the other side that im interested in. its hard to hold the tape on one disc whilst being about 1m away not like poopy liveaxle remember!
ok i got off my ass and measured it for those whod like to know.
By myself id estimate my reading would be no less than 5mm either side of my measured figure.
MA70 - 1555mm
MA61 - 1454mm
This distance is from the outside of the disc where it mounts to the hub (ie incl the total disc height)