Coil question

I have a Mallory electronic dist and my mallory coil was leaking.(Brand new) and went to replace. Had to replace with MSD Blaster (red) coil. Went for a drive and it drives fine but wont hold an idle. I have to keep the rpm at 2k or it will quit. By the way the coil is mounted horizontal if the matters.
Can the MSD coil be mounted vertical? Is it compatible with my Mallory Dist??