Just because the seller says "One of the Best brushless motor for 1/8 size monster truck", does NOT make it suited to 1/8th monster truck. The largest I would run a 7xl in is 1/8th buggy, and only that if it's a pretty lightweight buggy.

9xl will be much better, as rootar said, although 8xl might do ok, depending upon your final weight. Feigao's are cheap motors, and they get hot. I've begun to think that the xl series in general are not suited to 1/8th scale MT, unless you can do very low KV motor on HV LiPo.

J.