long bed to short bed question

[omar69chevy]

ok i have been wanting a 67-72 chevy ever since i sold mine but i cant find any decent shortbeds. i have found some great long beds for good prices. if i was to get a long bed and instead of cutting the frame under the cab like everybody does would it b wrong to cut it after the rear crossmember where the trailing arms are, putting some swb trailing arms and doing a back half. has anybody done this, i know there are alot of threads that shorten a frame under the cab but has anybody done it the way im talking about is there anything wrone leavin the body mounts it has? any help would be loved thanx guys