I recently bought a 1997 Blazer with a 4.3L engine. I wanted to fix the A/C and found that the evaporator was partially full of PAG oil and I have since blown out all the oil in the evaporator and replaced the Orifice tube and accumulator. The line from the accumulator to the compressor was dry at the accumulator connector; what else should I check? If the compressor still cycles in and out like before, and the whole end is turning with the clutch engaged; then the compressor is probably good, right? Would the compressor have too much oil?

 

Anytime the system has been exposed to air, the accumulator/dryer should be replaced before you evacuate and recharge the system. There's no way to know how much oil still remains in the system at this point, so ideally you would wanna remove all of the oil in the compressor and replace it all. In theory once the refrigerant vented from the lines, no more oil would be lost from the compressor, so if it was me I'd leave the compressor as is and just add a small 3oz can of R134a PAG oil through the low side after evacuating the system with the vacuum pump and before I'd recharge the system with R134a refrigerant. If you add too much oil, you'll leave less room for refrigerant and the system wouldn't work as well.
You'll want to attach a vacuum pump to the high and low sides by using an automotive R134a capable service manifold. Pull the system into a vacuum by letting the pump run for at least 45 minutes, an hour or more would be better to remove as much atmosphere (Oxygen which contains moisture) as possible, to achieve minimal contamination in the system. After you've finished the pump-down, close the valves on the service manifold Before shutting off the vacuum pump so that the system remains in a vacuum even after the pump has been shut off. Now let the system sit for a long enough period of time (15 to 20 minutes) to be sure that the system is holding vacuum and has no leaks, If the needles on the gauges move towards zero within the 15 to 20 minute waiting period then you have a leak in the system which is allowing outside air in, or your manifold gauge and or manifold hoses have leaked.
The final charge pressure / temperature is dependent on the ambient temperature. Your service manual should have a chart of what the suction pressure should be at specific ambient temperatures (usually fine tuned at 1000RPM and max cooling set in the interior, with the windows opened). Do NOT try to fill the system on the high pressure side, only charge on the low pressure side (located on the accumulator). If you find that your compressor clutch will Not engage when trying to add the refrigerant after you've added your 3oz can of PAG, which would suck in the refrigerant when you're attempting to add the R134a, then you'll need to jump the Clutch Cycling Pressure Switch with a paper clip until you get enough refrigerant pressure in the system for it to cycle on it's own.

 

A bit more information regarding R134a TEMPERATURE PRESSURE
http://www.mastercool.com/media/89660-INST_web.pdf