They are stiffer, because they are made for more weight. Installing these springs would lift the truck a quarter to a half inch, but would make the ride slightly more harsh. I remember years ago, when these tacos were new, we would have customers complaing of their truck leaning to one side, which was more noticable from the back of the truck than the front. Toyota had us put a v6 coil on the side that was lower. Worked like a charm, with 1 v6 spring and 1 4 cyl. spring the tacos height was even.