thanks Jeff
the ONLY reason for wanting alloy parts is the first truck cody had (rustler) I snapped the stock caster blocks with a half throttle crash. I put the alloy replacements in and never hurt them wit much more abuse. I wouldn't mine going to rpm at least cost wise but if I remember the last time I raced weren't there some t4 rpm arms broke? nothing is indestructable, but last I new metal was stronger than plastic. I could be wrong especially when it come to rc, I'm still in my first year and learning every day.