Question - these really are for my 71 camaro but certainly applies to any frame-off restoration. It seems one can get "stainless steel" frame bolts for A LOT more money than the OEM black oxidized, grade 8 frame bolts. This is especially true for my 71 camaro where its a sub-frame car THUS very important for the subframe bolts to be grade 8 at a minimum. Supposedly the stainless steel can go up to grade 16. The difference is $100 versus $30. Is it necessary to go ABOVE grade 8 or is grade 8 sufficient? Thoughts?