[FWB]

while i can't comment on a jag i was referring to coil over shocks. the bottom mount is usually an eyelet in most applications. the bolt runs through a sleeve the force is mostly downward. a bolt that is fully threaded is the wrong bolt to use, a bolt that is loose where the nut is will shear there. to compensate by using a lower strength fastener thinking it will bend instead of break is dangerous. any fastener for brakes , suspension or load bearing in the engine should be carbon steel, not stainless,,, stainless has wonderful anti corrosive properties but absolutely lousy strength. lets take a 1\2 inch bolt for instance a good quality carbon steel bolt will have in the neighborhood of 170,000 psi strength while its comparable stainless 18-8 ,304 or even 316 will have up to 40% less strength in fact if you check fastener suppliers stainless hardware doesn't carry ratings like other bolts......why.....
because a grade 3 carbon steel bolt will out perform the stainless one.
stainless for your intake manifold at 30 ft\lbs fine works for me but stainless on the suspension.....good luck.....grade 8 bolts are not all the same either it is a standard to be met to achieve the grade designation. some fasteners far exceed the rating.

a good place to see some info is actually on McMaster-Carr's web site they do show strengths of fasteners, as a comparison.