you can straighten alum but it is tricky we work on some postal trucks and they are built the same. use a oxy acetylene troch but use the gas only NO OXYGEN that is the right temp for alum. heat the affected area and hit with your hammer and back up with the dollys 3 or 4 times heat again and 3-4 more hits ect... if you do want to replace "yard store" has great deals on kits with guns , buck bars , clecos , ect... be careful drilling as the holes need to be precise . try to fix first and if it fails replace it . good luck