/windsor head 50 will fit dragster and roadster frames not exceeding 21 in width 51 ... and later factory exhaust headpipes 65 this header requires the use on hooker ... which will bolt directly to the stock mustang exhaust headpipes 67 header designed ... on right side 77 will not fit 1971-73 mustang/cougar with manual transmission 78 this ... transmission or borg-warner and top-loader model 4-speed will also need one ford ... this header requires the use of 1969-70 mustang 302 boss or 351 boss frame mount ...