Yes they will, the only differences were primarily between the Coupe/Conv and the fastback. 70s fit also as well as Cougar ones(69 &70). I will now go out to the shop and double check my other interchange manual . This one has several conflicts and I am going by memory on the ones I've changed over the years, this one say that the 70 Cougar one is the same as the fastback..instead of the coupe..which it says in 69 is the same. I'm pretty sure it is an error, although I will double check.
Yes, as I suspected, the one interchange is incorrect. The 1969 Cougar/Mustang coupe/conv. are the same as are the 70s. The only difference is the rear mirror mount from '69-'70. As long as you use the same year mirror you have several choices.