[Roadsters] Broken bolts

[Steve Harvey]

Last year I replaced my alternator with a GM and located it in the upper
right position on the engine. I purchased a Datsun mounting bracket (smog
pump I think) and attached the new alternator. The lower bracket is tapped
with 3/8-16 thread and the upper is 5/16-18.  Im using grade 8 bolts for
both fasteners. In order to align the alternator with the engine pulley I
made two spacers. The lower position spacer is = long and upper is 2-1/2 
long. I since the installation last summer I have broken one upper 5/16-18
bolt and two 3/8-16 bolts. All three broke clean two to three threads from
the bottom of the thread. When the alternator is properly installed the
alignment with the engine pulley looks correct and nothing looks out of
place. Im confused as to what is causing the shearing action on the
hardened bolts.  Has anyone seen this situation or may have a solution?



Steve

P.S. Remember a Vet this weekend