I would use it as is. But - are you sure that this is the bad part?
BTW if the rubber boot is damaged the interior probably is or will be soon
when moisture gets in there. The tie rods are normally good for 50-60,000
miles of average driving. More bumps = shorter life.
If you have not already done so, get under the car and have someone turn the
steering wheel back and forth about 60-90° and verify that all the slop is in
this part and not somewhere else. (If there is slop somewhere else too, you
should replace that part.)

The advantage of the nylok (TM) nut is that you don't have to have the hole
lined up. In other words you have an infinite choice of final positions.
Just be sure you have it good and tight. It won't come loose, I promise!

The ones that use cotter pins are OLD, and likely to have dried-up grease,
hard, brittle boots, etc. I believe they quit using cotter pins in about
1966 or 67.
--
George Downs Bartlesville, Heart of the USA!