Check David Pozzi's site b/c I think he has this stuff on it!! And I have posted it if you want to look for it..
And yes, the BB frame mounts are different then the SB frame mounts and there has also been made four different rubber, motor mounts!!
So to save yourself a lot of fitment grief, go with what your car/motor combination needs to be stock!! I did just to keep from having header fit problems.. pdq67
PS., and the BB sits over on the trans X-member about an inch, to the pass. side, too if I recall. It's all here if you want to search for it!!