The plates i got for the vette put my motor 1 1/4 inch forward,so i had to move my 700 forward and remake the crossmember.The thing was i modified my hooker sidepipes to fit ls1 flanges ,when finished the sidepipes came out right in the right location,if i had set the motor back the 1 1/4 inch they wouldve been jambed up against my rear tires,so it helped me by using them.