Originally Posted by bentwings
I use SS bolts on the heads with lots of never-seize and standard gr 8 bolts ont he collectors ...again with never-seize. I don't like using the SS bolts but rust is more of a problem than strength.
Stainless has a higher thermal expansion rate than steel. Basically that means if you take two bars of equal length and heat them up, one stainless and one steel, the stainless bar will grow longer than a steel bar. Therefore every time the engine heats up, if you have steel headers and ss header bolts, the bolt load drops.
Steel bolts are a better choice for this reason.