Oh, for flushing, I didn't use an agent. I blew lots of compressed air through each part of the A/C system (except the new drier and compressor). My system did not have a compressor sieze up on it or anything though, if you have had a failure other than a simple leak it is probably necessary. All my lines looked clean on the inside. Actually, you probably should flush regardless.
Just rode home in cool comfort tonight.
I really thought it would slow down my 240 more than it does. That big York really isn't rough or noisy at all, I heard some people saying stuff like that about it, but IMHO it is quieter than the ones on most modern cars.
Does anyone have advice one way or another about the amount of freon I used?