My 70 Mach 1 is going through a rotisserie restoration. It will be in the resto-mod class when completed and I will "show" the car initially. I currently have NEW leaf springs with factory traction bars. Although I Do plan to drive my mustang after I finish showing it, it has been suggested that I replace the "old school" rear leaf spring/traction bar set up with a modern four link set up, especially since I am replacing the front suspension with tubular A frames and coil overs. Can someone with "show car" experience tell me how big a deal a four link suspension vs an original leaf spring suspension would be to a resto-mod car judge? Is it significant? I hate to spend new money to replace new parts already on the car if there is little negative to a show judge. I will eventually drive this car but do not plan to road race it. This mustang has always been a straight line "street light to street light" car. I know this because I am also the original owner. Is the upgrade to four link worth the expense in a resto-mod Show Car competition, even though I do not plan to road race the car once it's show days are over? Are there any Car Show judges out there to guide me through my inexperience?