If you have the kit, use it and do not worry about it. You are talking street car with 4 speed, you will be ok. My car is a drag car with 33 inches slick and 9 second time slips, trans brake. I will use the scat crank in a street aplication all day long and not worry about it.

Note: the trans brake is worse than 4 speed. Like dave says because of the radius, the scatt scrank is stronger than any factory 360