is it ok to loosen and re-torque? Reading elsewhere that the clamping force will not be right if you already overstressed them. Also saw some discussion of the way the threads lock they can be retorqued to increase but should never be re-used once backed off. I know my rusty old bolts need replaced, but seeing posts here about ones that were impacted on and wondered if they should be replaced. Or is that just hype from people that want to sell bolts?
Also what's a good source for new bolts. I have 7-1/4, so they are only 7/16". A lot of the bolts i see available are plated, not black like i believe originals were. Does anyone know for sure what is correct grade? I would think that could make a big difference in torque, clamping spring movement...