I didnt see yor post till just now, but I did this to day and thats exactly what you do. Just be careful not to get it too tight..

 

you can swap them over for the the mirrors i had on my 89 sport. don't have a picture but they where sleek, black and smaller. all the wind in the world would not move them.
check e-bay for them there cheap and bolt right up. you can even get ones that are adjustable from inside the cab like mine.
i swapped over my sleek black ones to those dumbo chrome ones so i could haul a trailer. there interchangeable.

 

yeah those black ones are nice. my truck came with them. but if you live in a neighborhood like mine where other people don't know how to drive and don't care for the saftey of the children, they tend to get to far to one side of the street and take a few of them mirrors down the road with them. already had a couple of them drift too far and take out a couple of my neighbors cars...just waiting for that fateful day where i walk outside and see my truck parked V.I.P. for me on my front porch...

 

never had any problems with them. don't think there going to put anything unsafe on the rig.