Do not use stainless steel bolts on portions of the kit that utilize a pinching mechanism. Examples below.
FBL Head Block
Main Shaft Pinch Collar
Engine Fan Hub
Why not use stainless steel bolts?
Stainless steel screws are much softer than hardened steel screws. When used in a pinching application the bolt may stretch and cause the pinching mechanism to not securely grip the mating part. Recently a customer complained of the main shaft collar slipping, after inspecting his helicopter I noticed he had replaced the 2.5mm hardened steel bolt with a stainless steel bolt. I immediately changed the main shaft collar bolt back to a hardened steel bolt and the problem was gone.