Doesn't that trans have a transverse style mount? If it does you will need to weld an arm on a cross member. Pick any one that is the right width and weld the arm on. I'm not in favor of destroying original equipment either. Trying to tell you something that will work. Had this problem on a 70 Trans Am I bought that had a newer style trans in it bolted to a Chevy. It had a custom cross member. I wish I would have kept the cross member. I would gladly pass it on.