i am about to do some work on the a/c since it all leaked out last time i did the head gasket job.
The system was running fine before.
The a/c line to the condenser was left disconnected for around 2 weeks during the head job.
New drier is about to be installed.
Also system should have no leaks.
What should i do first? Flush the system first or install the drier first then flush the system?

After that i am about to fill the system up with r12. the tag on the raidator support is saying 2.4lbs is max and i only have 2.25lbs on my hand right now, would this be enough or i will need more?
and how much oil charge should i be using?

Any advice would be helpful

Thanks