What are the shift points for my transmission?
1998 Express, automatic transmission, 5.7 VorTec with 3.53 rear end.
I can feel the shift into second, but after that it's hard to tell. It's a conversion van but I usually drive it empty. Trying to drive for economy.

 

You think that's hard, try figuring it out with a 6 speed auto transmission. :-)

Im just easy on the pedal and I'm getting close to 14mpg. It took awhile, but my mpg improved from new.

 

I assume you mean 3.73 gears.....
I have a 2002 same engine 3/4 ton with the 3.73.
After second it goes drive then lockup torque converter then into overdrive. when it shifts depends on pedal position, and load on engine.
You can buy a dash mounted computer that will give you more control of shift points and also fuel economy readings.....however I doubt that you will save enough $ to warrant the expense.
Our vans suck on gas plain and simple.
Best thing you can do is make sure of the tire pressure, and that its tuned up. Some tires have less rolling resistance than others....but then those tires would suck in cold temps.