I have a 1970 model and was looking to replace this molding, it is on the front fender close to the window and has a rubber deflector attached to it. In looking at it, it appears almost impossible to remove without removing the front fenders. Can these be removed with the fenders in place and if so, what size wrench would be involved? Thanks!

 

It's been a while since I had mine off for paint (1998) but I painted the fenders on the car then installed all the chrome later, so I'm fairly sure they are accessible with the fender still attached.

I don't remember the exact size but 3/8 or 7/6 is my best guess.

 

I think they are 5/16ths.

 

I changed mine on my 70 442 recently. It was tight but no need to remove or loosen fender. I used a thin wrench, maybe 3/8ths to R&R the stamp nuts. On the new part I had to trim one of the 3 studs (outboard one) due to interference with the chrome piece that runs under the fender. It sure looks nice when done.
Have a magnet handy since you will drop the nuts, I sure did.