HEI conversion help
Ditto post #4. Don't cut any factory wires. Remove your ballast. Connect the two connectors together. Neatest is using a male-male "spade" (56 terminal). They exist, that is what I did, and I heat-shrinked over it. Otherwise make a short jumper cable w/ male-male terminals.
For those w/ a "dual ballast", leave the terminal that went to the ECU hanging. You have 2 terminals (in parallel) on the +12 V upstream side. Use either one and leave the other hanging.