Here is a supplier that is well thought of in the racing commuinty. They have a good bolt selection in AN sizes for both shear and tension applications.
One thing that has not been mentioned is the diameter of a typical grade 5 or 8 bolt can be off size by several thousandths of an inch allowing for a loose fit in a drilled hole. Whereas a AN bolt is more closely sized to a coresponding hole size for a much better fit. You wont see and Grade 8 stuff on a real "Race Car".
http://www.pegasusautoracing.com/adv...oryID=HARDWARE
Rick