What Grade nuts for Ball Joints?
 

Hey all, I'm still doing my front suspension and I got the FMS lower control arms which surprisingly did not come with new Castle Nuts for the Ball joints, I really don't want to re-use the nut I took off my stock suspension. I went to Lowe's and was looking for Grade 8 Castle Nuts but the highest grade they had in Castle Nuts was Grade 5, what comes stock? Is Grade 5 strong enough for a ball joint? I certainly don't want to DOWNGRADE from stock epecially since I am putting all higher performace parts on it. Does anyone know where to find Grade 8 castle nuts?? Thanks guys!! :)