I think the 18 SS would be overkill. You will never be able to get all that power to the ground. The Rush is already too heavy, and the .18 SS will only add to that problem.

I would look at the smaller, lighter high reving .12 engines like the OS CV-RX.

I think stadium trucks are a lot like F1 cars. And putting a .18 SS would be like dumping a high torqe low revving NASCAR V8 into the back of a the Ferrari F1 car. It would make the car almost impossible to drive.

But it wold be fast!