take care of the transmission and have the oil/filter changed: 30K if you pull often.
most trans are ruined by lack, rather than over service.
I think this quote says it best:
Quote from other guy:
_________
I think you run into problems when you modify the engine to produce more horsepower than the transmission was designed to handle. I tow between 60 and 65 MPH and average 14 miles per gallon on the open road.
__________
This engine is fairly easy to modify for more hp, soon you past the design limits of the trans and trouble starts. then the owners blame the sorry transmission, when in fact, excess hp, brings on harder use as it pulls harder and the owner dishes out rougher treatment.
until it blows, the weakest point blows, the transmission, if they had spent the same or more money beefing up the transmission as they did on the motor, then maybe it would have held up and never tow more than the recommended load limit.
but, some folks think that black smoke pouring out of the tailpipe is a sign, they are driving an 18 wheeler tractor.