i have a 72 B body, same K member as E body, with a 572 hemi and tti headers. i used schumacher mounts without cutting anything. the schumacher mounts raise up the motor about 1/2" and move it to the passenger side about 1/4" over a stock hemi k member.
in other posts people have reported greater success and less problems with the arzura, spelled wrong, mounts. do a search on this subject and you will find several threads. this question shows up every 3 months or so.