Thanks for the great info. Emailed Raydon directly from my work email and received a
very fair quote since they do business with my employer.
Some good information for future searches:
the 3300 series is the same as the 3600 series minus the lock in/out feature. saves $15 bucks or so a pair if you dont require that functionality.
500# rating is for static usage, and is for an 18" slide extension tested at 100,000 slide cycles.
260# @ 60 inches tested at 100k cycles static, and 156# @ 60" while enduring dynamic loads over 100k cycles.
Essentially it is best to set the drawers up so that the heaviest objects sit in the back of the drawer to maximize the working life.
The 100# slides are sold in 2 inch increments from 10-32"
3300/3600 series diagram and info:
http://ryadon.com/docs/I-DS-3600-SERIES.pdf