Your tires at max pressure can carry 1760 lbs each or 7040 lbs total.
Your trailer has a GVWR of 7436 lbs. If 10% of the trailer weight is on
the tongue that puts 6336 lbs. on the axles. So max pressure will give
you about 175 lbs. safety margin per tire IF your trailer is loaded perfectly evenly.
Your tires inflated to 42PSI has a
carrying capacity around 1550 lbs each or 6200 lbs total which would have the
tires overloaded when the trailer is fully loaded.
While the below link is a load chart for Maxxis tires, all ST tires will be very close to these figures.
http://www.maxxis.com/Repository/Files/m8008load.pdf
Edited by: hhh