Instead of replacing/repairing the spade connectors there is a better way. Remove the bulk head connector. Cut the terminals from the black wire on both sides of the connector. Drill the bulkhead (both sides engine and body) where the wire went through to the same diameter of the wire. Run a piece of same gauge wire thru both the engine connector and the bulkhead. Use this to splice between the two sections. Use high quality splices not junk. Make it long enough so there is some extra under the dash. That way if you need to pull the bulkhead off you will have slack. You can always cut the under dash side for complete removal. The spade connectors get corrode/loose increasing resistance. Then they heat up. This way you are rid of them. Looks factory. You can do the red wire as well. I've been running this set up 17 years on my Challenger with a 110 amp alternator. Gauge still functions. No over heating of the wire.
Doug