Fender Tag decoder for a '66 Mopar 615 = 383-2 bbl 270 hp 625 = 383-4 bbl 325 hp I'm assuming there was something also different about the engine ie; compression.... other than just a 4 bbl that increased hp by 55 hp. Does anyone know for sure?
The 2-barrel had 9.2/1 compression. The 4-barrel had 10.0/1 compression, requiring premium fuel. '66 Chrysler brochure: http://www.lov2xlr8.no/brochures/mopar/66chryl/66chryl.html You'll find the engine specs on the last page in the fine print.
