Identify this carb?

My '75 Duster 225-6 is basically all original, except for this rebuilt carb. I'm sure it's a Holley 1945, although there are no such markings on it. Just below the reman red tag on the passenger side are these stamped #'s (top to bottom): 3830576,7319,2574. Can someone tell me exactly what it is for, & the date code? My research so far says it's for a Dodge truck, dated 257th day of 1974. Am I close? - Dale