Do you have a set of calipers? This is a digital set, I have both digital and analog, and come in handy for building.
https://m.aliexpress.com/item/32958290585.html?gatewayAdapt=Pc2Msite
I'm assuming traxxas tmaxx may fit, if not, axial or stampede size, but this is if I had to guess.
Both the ball ends come in different sizes as well as the threading on it. Do you have any rcs you can take a steering or srm link off of?
I'm assuming your building a 6x6 or 8x8?