I've picked up an HEI distributor to place in my '66 chevy p/u. The distributor is the type with the external coil. After installing the distributor I realized that I have to make a decision; do I try to modify the coil plug wire to fit the old coil, get a new coil, or get the type with th integrated coil in the cap? Would the old coil even work to correctly power the HEI system? What are your thoughts?