I have a evinrude 70hp outboard and your online configuration didn't have option for 70 just 75 so what size would I need for that for our pontoon

We consider several factors when sizing the TurboSwing®: the make, horsepower, and cowling size of your motor. If necessary, you may move up a size. However, due to possible contact between the TurboSwing and the motor, we do not recommend moving down in size. Thank you.