Birdie, with your little four banger, you will not get much compression braking anyway. But it is not like you are running 18,000 gvw.
If you come out West and you see that sign which says "Warning 6 miles 6% downgrade ahead. Trucks use lower gears." You would be well advised to grab the shifter and select a lower gear. About 3'rd on a five speed, 3'rd on a four speed, or 2'nd on a three speed. Even if you are only carrying 1000 lbs in the back.
You definitely want overdrive locked out.
Then apply brakes judiciously to keep the engine well under redline.
It is a hell of a lot better to hit those downhill freeway curves at 50 mph and have the full potential of your brake system to bring you to a stop, than it is to watch the speedo creeping toward 80 coming into a turn and your brakes have already faded to nothing.
We have been using the tranny this way since trannies had two speeds. A few weeks ago I was selecting gears on a 2015 Chevy with a six speed towing a 5000 lb boat down into and back out of Hells Canyon.
Frequent shifting, slipping clutches or bands, and high heat are the destroyers of transmissions.
