Hi,
I ordered the ones that Fx linked in the thread he linked above, I haven't recieved them yet, but they look like there threaded in the pic, if they are great, if not I will drill if needed and use a screw and nut, I will use a nut anyway.
Are you hitting things when they strip? anyway, 2 things check if your servo saver is too tight I think they want about 4mm of thread under that nut that adjusts the servo saver, another thing is the weight of the truck, well in either case you don't want that ut too tight, look in the X version SS manual and you will find what they recommend for the tightness. If you use ALU horns make sure you adjustment is correct or you may damage your servo!!!
In the end n mine the reason it striped was, I didn't know about the different size horns for different servo types, I only had an RTR then so when I upgraded my servo I just used the horn that was there and made it fit, it was a futaba size horn on a hitec servo, that will strip very quickly, on steering anyway.
John