RE: MPI clutch springs
i went to my lhs and did the same as you. they where out of the traxxas spring, so he gave me an mpi spring. set of two, said they wher the same thing. the ones i got are a little longer and smaller in diameter but stiffer. the spring fit's with no problems. i've been running this spring for 1 or 2 weeks, works great. it does enguage later then the stock spring.