I plan on buying a tandem axle trailer this spring. It will be used for mowing, landscape installation, sod etc. This will be my only trailer. With that said they come standard with 3.5 k axles. My thought is to upgrade to 5k axles. It raises the cost by $400.00. Main reason being tandem can hold 8 yards of mulch with ease but, but the wight will be around 8k. Standard payload 5.5 k on 3.5 axles. Any comments on running heavier setup?