I replaced my 1970 GT rear axle with one out of a 1973 GT last night. I've replaced shocks, control arms, etc. in the past and never had a problem with things lining up; however, I really struggled with all of the attachments last night. I connected the lower control arms and shocks without a problem but the cross bar (I don't remember the technical name for it) wouldn't attach to the axle. It appeared to be about 1/4" too short. I then unattached the shocks and control arms and was able to attach the cross bar. I then reattached the shocks and attempted to attach the control arms; however, one appeared too short and the other too long (like the axle wasn't square to the car. I finally unattached the shocks, attached the left control arm and was able to get the right control arm bolt in place by having my son pull back hard on the right side of the axle. It is my understanding that the 70 and 73 axles are interchangable. I've checked the parts book and the rest of the axle attachments, (control arms, shocks, etc), have the same part numbers from 69 through 73. Has anyone else had this problem? Have I missed something?