I have a buddy that is converting his 62 Impala from gen to alternator and he is having a hard time finding a bracket to keep the alt in the same place as the gen. Any suggestions?

If he is still running exhaust manifolds, he would have to find a 63 or 64 manifold as the lower alternator bracket bolts onto the manifold. I would suspect the lower mounting bracket is different for the generator and alternator. The upper bracket is a simple strap of metal and fairly easy to locate.