timing related/ broken cam?

Hi i bought an LT with a broken cam, bought new head with cam all ready to fit. put it all together and cant get it to run unless its bump started! will run and rev up but ever so smokey, so tried advancing and retarding the fuel pump but still wont start from off the key! tried altering the the pump timing by 180 and tried changing the cam by 180 , it still wont start off the key! driving me mad now so if someone could help i'd be ever so thankfull.