Hogwash on the 170 at speed stability! I can run mine at 60 all day long with no issues. Everything has been rebuilt and properly installed/adjusted with stock suspension, steering and brakes. I did add a Wilwood dual master cylinder for redundancy. I am also running IROK radial mudders. With the BW overdrive the 226 just purrs along and the miles/smiles pass by effortlessly.I have restored two FC’s. They had much better bodies then yours. I mean bodies with no rust and like it came from the factory. Excellent paint. Had to rebuild all the running gear. I have over 40K in it. If i had this i would part it out. FC parts are very hard to get and there is a demand. It is my opinion that your body can not be restored. It would take a large body shop hundreds of hours to get it right. FC’s never reach highway speed. Max speed is 45 mph and with overdrive 55 mph. At 55 they become unstable and are really unsafe to drive. I hope i did not throw cold water on your project but in my opinion it is too rough.