Stainless fatigues quickly does it not?
I once saw someone try and fit stainless bolts to their rocker cover on a YB engine. He started getting pissed off when they wouldn't tighten down screaming things about stripping threads in the soft alloy head. So he fitted the original bolts which tightened up. The bolts were rated at the same strength but upon comparison, the stainless bolt had grown almost 5mm.
Do
NOT use stainless on load beraring components...
What About Stainless?
Replacing the OEM-plated steel fasteners on the outside of the bike provides a good-looking, low maintenance cure for rusted nuts and bolts. When contemplating replacing OEM fasteners with stainless steel, remember that common stainless steel does not have the strength of common alloy steels and should not be used for critical, highly stressed applications. The stainless steel also has higher friction than steel does which gives less preload at the same torque. When in doubt, keep the OEM steel stuff for critical applications.
Also the yield strength of stainless bolts is lower that steel.