Can I use DOT 5 in this MC?

The thing I have heard about it is if moisture gets into the system it tends to collect on a low spot. Rather then being dispersed into all the fluid.

Personally I'm not too worried if your system is properly sealed.

if someone is worried about that then just bleed the brakes every spring and be done with it. i have been running dot 5 in our dart for close to 10 years now and haven't bled them or had any issues with them.