You people up north
Changing out the orfice? Go to the variable type orfice "VOV".
A newer condensor design stacked plates far outperforms tube style. http://www.vintageair.com/
When purchasing new parts like filter dryer from GM you'll see update information requiring more r134a in burb over what it came with stock. I used the extra r134a and I can't drive with with any setting over low, even mix some heat for more comfort. Remember, I'm in the sub-tropics, burb is flat black and it's surface gets real hot when parked.
99 GMC SUB, 2500, 4x4, 6.5 TD (F) #H32 enhanced blk, Phaser timing set, B&D IC, 3" ATS exh, K&N w/prefilter, 4WD NVG 246, 4L80E kevlar Transgo off road/tow mods/B&M supercooler, 14 FF MagTec w/locker 3.42:1, 9.25" IFS frt/diff 3.42:1 w/ARB locker, AutoMeter Boost & pre-turbo pyro meter, 12,000 lb hydro winch, Warn classic bumper w/brushguard & diesel scoop, Max E-torq Stage 3, hi pop inj, oil bypass sys, on board air comp for front ARB locker & tire inflation, DynaView driving/auto-cornering lts, DZ nerfs, A/T 285/75/16 SilentArmor 3750 lb rated on 3750 lb rated Alcoa, 3 IP drivers 2 r spares.