voltage drop at coil

hello everyone...i have a 67 chevelle big block that will not fire....i have 12 volts at the coil, butr when i turn the engine over it drops to 9 volts. i tried running a wire directly from the battery to the coil and it starts fine...my problem is from the battery to the coil...need help.

thanks,
ken

Did you upgrade to an MSD system?
If you try to use the resistor wire for points systems to run MSD you will get a drop exactly like that...
If thats the case you need a new ignition power wire to the coil...