need some info on mc conversion

guys I have a 1965 polara and it has drum brake all 4 corners and today I started my front disc. brake conv. and that went smooth until I got to the master cyl. the factory one has only 1 brake line and my new one is from a 70 imperial with 2 brake lines coming out , I was told that the new mc would bolt rite on well when I took the single mc off it wouldn't come off after I removed the 4 nuts what I had to do is take the 2 bolts off the back side of it and it came off leaving the plunger behind on the brake rod is this normal and do I need a different brake rod for the new disc. brake master or does that plunger pull off the brake rod as soon as I get this figured out I can move on .


Please help

Thanks Mike