Are you stuck on .28-.32 size motors? Im willing to bet that a RB WS7II X3 .21 will walk all over their TM728. Bigger doesnt always mean badder. If you are going to spend $300+ on a motor why in gods name would you want it to be a pullstart?

You will be lucky if a pullstart lasts a quart of fuel. Spend the $80 for a decent box and make sure you get a motor that you can handle. There are so many motors out there that people just want to slap on something huge and its so fast they cant control the car.