Master cylinder fluid

[kenwheeler]

I have an 87 without the quick disconnect fluid line. I'm installing a new master cylinder hoping this will fix the my lack of any useable clutch pedal. I can't bench bleed tha master because all the fluid will run out before I get the master installed. Can I rig a tight cap on the end of the line, bench bleed the master and limit the evil air intake by removing the cap after installing the master?