It would bolt up fairly easily with the right driveshaft but you would have no speedo due to no speedo drive, but it is a 85 635 I have heard that tranny can have a speedo drive added since it is basiclly the same as the 80-81 5-speed. Engine management should be straightforward since you have a doner car, just don't throw anything out until you are done. Should be lots of fun if you decide to put it together. Mike W.