Originally Posted by J_Bone

I run the Traxxas uppers and TLR lowers too. You can run Traxxas lowers, but the TLR lowers are taller and give you more adjustment.
I'm going to be running Avid springs on my T4 soon. I personally have not used Losi springs. I went strait from AE to Avid. But from all that I have read over the last 6 months, Losi springs didn't improve lap times in the trucks. Buggy guys liked them and they seemed to improve performance in buggies, not the trucks. So I stuck with AE till Avids came out.