Yes and No, They are not the correct design first of all. Some guys use them to get extra clearance for tires with their hot rods so they work well for that but in doing so create an issue with the stock rear seat springs because it reduces the inner space distance between well panels.
Hi Dick, thanks for your reply. I was thinking of using them to create more room for wheels and tires. I have heard that I would need to modify my seat base, but I was thinking of using a different rear seat anyway. I thought using the roadster/coupe ones would be easier and look better than making something from scratch. Can you recommend a supplier?.