"Thanks for your support- - - - -!"

One thing some folks don't consider when substituting higher-grade bolts is that the nut must match the bolt. If it's going into a threaded boss in an engine block where the female thread can't be upgraded, it might not be a good idea to go with a higher-rated bolt than original, especially in the case of cylinder head or main bearing fasteners. I have substituted studs for bolts on occasion on cylinder heads subject to high compression and RPM situations, since it's possible to use much higher torque numbers when the stud isn't turning in the threads in the block as the nut on top is being torqued.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!