I have a 66 with reproduction K,O,s with pins. I have never used the saftey pins.
The most important thing to know is they are directional and have to have the correct one on the correct side of the car.
I have heard some horror stories from KO,S coming off.
I can tell you personally I have never had a problem with mine. Had them on and off the car probably a hundred times.
What I do is spin them on by hand with the car up in the air,I then whack them with a lead hammer 2 or 3 times to kind of set them thenI set the car back on the ground and give them a couple more hard whacks, I often give mine a hit just to double check and i have never found them loose.
A couple years back ran into a new C2 owner and he was asking me how to deal with the knock offs. I took out my hammer and showed him how to WHACK it. the man was speachless, I then said if he is not hitting his as hard they could be loose. I went to his car and sure enough each time I wacked it the spinner moved. his were loose from the previous owner. and this guy was love tapping them because he was afraid of swinging the hammer.
Good luck and welcome to our forumn.
I learned how to deal with mine from another vette owner who showed me the differance beween hitting them on and whacking them on.
If you get a chance let us know about your car and ictures are always welcome