73 CR400 engine in a Mag frame ?

Will a 1973 CR400 engine fit in a Mag frame with the proper mounts ? My Mag cases have been repaired a couple of times and are still cracking . A good set almost goes for the price of a whole bike and anything else I've found is severely eroded . I'm thinking of going with a 400 in my frame and getting beat by a whole other set of sandbaggers .

Hi
I have a number of cr400 engine cases in various states of disrepair - I could send you a pair to see if they fit? (I think I have some real gnarly ones that you can have!)