273 Numbers Matching car. Should I rebuild or swap engine?

Dodge had a 275 horse 273 in the D Dart in 66. It was specially built for drag racing. They only had the the 2 barrel engine in 68. 67 was the last year for the 235 horse engine. "Commando" was the name Plymouth gave their 273 4 barrels and Dodge called them Charger 273's.