How do you know it only weighs 1000 lbs? Scale? Or 'paper'?
The tongue
weight should be 10-12% of the actual total weight. So, if you weigh the
axle and tongue jack weight on a scale, loaded for the road, and it all weighs 1000 lbs, then 100-120 lbs of that should be on the tongue.
OTOH. if you are using 'paper' weights (Manf brochure, frame tag,
title, etc.) and it really weighs 1,500 lbs loaded, then TW should be 150-180 lbs. My 91S13 weighs 1,700 loaded for the road.
Too
light on the tongue is a setup for sway; err on the heavy side.