Question about length of the spacers. I have been looking at 4" and 6" rear spacers. My hills are pretty steep. Is there any down side to going with 6" as opposed to 4" ? I am thinking wider is better but don't want to make it unstable. Wheels will be outside the fenders but I don't really use it in the rain or excessive mud. You guys have been a wealth of knowledge. Speeding up my learning curve. Thanks for all the info.