Grade 8 Vs Stainless?

[camoit]

One of the big difference between grade 5 and 8 is the elasticity of the bolt.
Grade 5 has a larger range of stretch VS grade 8. Grade 8 has a smaller range of stretch and shrink. So they will hold better but will snap easier if run out side the designed spec. While a case hardened bolt is harder to break but has less stretch then the grade 8 and is good for things like frame to spring hanger connections but bad for things that get hot and cool off. Stainless is good for things that corrosion is a problem like the header.

[Maxxheadroom]

One of the big difference between grade 5 and 8 is the elasticity of the bolt.
Grade 5 has a larger range of stretch VS grade 8. Grade 8 has a smaller range of stretch and shrink. So they will hold better but will snap easier if run out side the designed spec. While a case hardened bolt is harder to break but has less stretch then the grade 8 and is good for things like frame to spring hanger connections but bad for things that get hot and cool off. Stainless is good for things that corrosion is a problem like the header.

This is mostly true, however you will find if you mix stainless and carbon steel like using stainless bolts on your headers over time they will seize worse than a carbon steel bolt. The two metals react with one another, it gets ugly quick. I just removed a carbon steel gearbox from a stainless shaft. The gearbox had been in place for a little over a year, I had to cut the gearbox off the shaft it was seized so badly. Just something to keep in mind, if you insist on using stainless anti-seize will make your life a lot easier down the road. Anti-seize will also help prevent the bolt from galling when it is tightened.