I have the 15x8 & 15x6 conical seat cragars on mine. They seem to work really well. Haven’t loosened up after a couple of years. I like them better than mag lug nuts.
If your studs are long enough, they're fine.
I don't know much about the new Cragars, (the only cragars I own are a pair of old supertrick skinny fronts) but my new conical seat torque thrusts have about a half inch thick centers, and I bet that isn't real safe with a stock 3/4" long stud. Maybe 5-7 threads in the lug? I would prefer a shank mag lug with 14 threads, thanks.
The conical wheel works for me, cause everything i have already has 3" studs, front and rear.
I might be ticked off if I found out I had to change 20 studs, and maybe pull the axles to do it, just to put on my new conical lug wheels.........