Running rich how do I fix.
You didn't tell us your cam specs. Also, your 351w with a 302 firing order means someone put a 302 cam in it and it now needs that order. You can't change that unless you get a different cam.
Is the new carb. jetted the same way the old one was?
We need more info on your setup....heads, cam specs, gears, intake....
351w(.060), ported & polished heads with 1.94/1.60 valves, 10.3 comp, stealth intake, 274XE cam, Holley 750 dp, Mallory dist., shorty headers, flowmasters, 4:10 gear, c-4 with 3700 stall converter, subframes, electric fan