You have an automatic or a manual? If it's an auto lock it out of OD and watch your engine temp, if it starts climbing your transmission is getting hot. Let it idle in Neutral for a few minutes once you get there so that the trans can circulate fluid through the heat exchanger. If it's a manual you're good.
$600 for a Goerend or Suncoast converter is money well spent on an auto for both fuel mileage and trans longevity when towing. And a 366 (3200 RPM) governor spring is money very well spent for power and fuel mileage gains. As long as you drive it like you do now when you're empty.
If you haven't already, put your headlights and tail lights on relays. As it is ALL current for the lights goes through the key switch and the headlight switch and the wiring is barely inadequate. Adding trailer lights doesn't help the situation. If the trailer has all LED's you are probably ok on the taillights, but definitely do the headlights.