I ran the rpm's up front, but for racing, I liked the stiffer arms, the rpm has alot of flex.
They must have redesigned them, They were discontinued at one time, yeah they are a must if you ask me.
yeah the 5t tank is 150. I ran it on my revo, any truggy tank will work with the tekno kit though. I just hated the 3.3 tank, it leaks around the cap to easily