I just swapped my engine out for a .40 bored 350 with a mild cam in it and it ha no power increase over the old tired engine. When cruising down the road or aggressive driving I get a code 43 and 45. Gas mileage is worse than with the tired engine. Timing is right on 0 degrees and the distrubutor is all new, including the module. 02 sensor is new knock sensor is new What could this be? Vacuum is reading strong so I don't know what the problem could be. Any ideas??