ok so i was driveing my car for about a summer and decided to check my timing and it was at about 8* and i put it back to 0* but the car boged really bad so i put it at about 4* and the car ran good for a day but now it bogs worse than it di at 0 can anyone help me what might be the problem?

 

mine is at 4* or 6* and she runs great.mine had a real bad bog and surge at idle it had 4.3 injectors in it so i put 350 injectors back in because i couldn't find any 5.7s at the u pull it yard..could be something else maybe misfiring or bad fuel spray,vacuum leak.etc

 

i kinda got rid of the bog a bit but the car is really roughf when i try to get on it cuold that be a bad u joint?