hi i have a 2000 chevrolet malibu..duh right im in this thread.. either way it has the 3100 engine in it. i wanted to know if a older 3.1 or 3.4 head will fit on it. the reason.. i can get 2 3.4l heads from a junk yard for 50 bucks or i can get the 3.1 head from a junk yard for the say gen engine for 150 any information would be great thanx for all your help