1995 GT outpost: replace stem?
 

I would like to replace the hi rise stem with something shorter and bring it closer. I want to keep the wide handlebar.
Does anyone know what will fit?

Your GT uses a quill stem. You could replace it with the same type but with the rise and reach you seek or you could replace it with a quill to threadless adapter and find better availability of stem options.

Is it just a matter of measuring the diameter? What about length?

I replaced my quill stem on my 93 GT with a Cane Creek 40 headset, but I was replacing the fork. You could inexpensively find a shorter stem on the cheap. Nashbar ATB Comfort Quill Stem

thanks for the link, do you happen to know what options I need to select?

OK once I took out the old stem, the measurements all made sense. I bought 1 from ebay, I like the results. I also have road tires on it now. can't wait to ride it.

Excellent results. Thanks for posting a follow-up of what you purchased and installed. Lots of times on this forum we never get to hear or see the "ending". This is a rare treat. Good luck I hope it all works out for you.