Fiber syncros in a T5 trans question
 

My 88 2.8 5spd has always had a sticky shift in all gears butespecially going from neutral to first gear. I recently learned that my trans is a T5 world class which may contain fiber type syncros? I'm not familiar with fiber syncros and was wondering if these wear faster than brass type? Why did gm go fiber? Are there brass replacements? I'm thinking of getting a o/h kit and wanted suggestions on better replacement parts. Odometershows little under 40K but I bet actual is 140K since it doesn't show over 100K. Thanks for any replies.

Mike