im not sure how much work you are trying to do to the frame or your truck to get this frame under it. but you will have to channel your cab floor for this frame. the frame horns were joined to the new rails to far back.
I would jump on it even if you have to add some bracing or new welds here and there its still a cheap frame that can be worked on while you drive your truck and that is what matters not losing the ability to drive your mini no withdrawals