Does grade matter? (bolts)

[Jon89le]

In regard to our exhaust manifolds, does it? I wanted to get new ones and the local shop only had grd 5s an not 8s. I got the Grd 5 ones but will these good enough? I know the grade is related to the tensile strength but im worried that the constant heating and cooling of the bolts and slight tugging from the exhaust system will break them. Any input is appreciated. Thanks

[Guest Anonymous]

Why do you need new bolts? Unless something was wrong with yours, I don't see the need for new ones.

[Jon89le]

I figured i'd get new ones since my old ones are 14 years old. Just being cautious I guess. I'm doing the whole motor so I am replacing most of the things.

[Guest Anonymous]

Well that's your choice to replace them but I would replace them with ones meeting factory specs. (grade 8)

[Steve LS]

You could get the exact bolts from a dealer. Otherwise grade 5 is a tough bolt. The #2 or 3 that some hardware stores sell should be outlawed. The problem with grade 8 is if you use them and they set up and bust when trying to remove them they will be a bitch to drill and remove. Grade 5 is most close to what would have been in there.