Considering making any modifications at all to your existing mirrors will be detrimental to your vehicle, you need to think of an alternative mirror solution.
My dad (1963) bought a set of these and used them for years. When he died, I got them and used them for years also. I used them until about 2005 when I purchased my first dualy truck that came with towing mirrors, so I ended giving them to someone else. As far as I know, they are still being used.
The simply attach under the front fender and then the L clip hooks under the hood of your vehicle. The turnbuckles let you tighten them down, then you adjust the angle of your mirror. When not towing, you just take them off. Get 2 so you can put them on each side of your tow vehicle.
They may look a little funky, but they do work well and have been time-tested and proven since time began. And amazing, this design has never changed. They are almost identical to the set my Dad had in 1963.
Click here.Just noticed, at the top of that page, there is also a door mounted mirror, similar to this one. Check it out too. It might work better for your needs, depending upon the design of your truck.
