I have an MSD 6a and MSD blaster 2 coils in my 85. when i bought the car they had the MSD running to both coils. someone on this site told me that it should only be powering the leading coil. so i hooked the trailing coil back up to its original connections and everything seemed fine for a while. a few days later when i was tightening the belt and started her up i noticed the trailing coil was on fire between the positive terminal and the wire connection. whats up?

I beleive you have a bad coil. If there were any cracks on the coil casing it will leak oil and catch on fire.