the msr4's are nice shocks. you will need to get some better shock shafts though. the nitrate coated shafts for the traxxas shocks are the best that i have found. they are the same length and size as the msr4's. you can buy them from m.i.p. or traxxas. the piggyback helps by reducing air bubbles and allow more fluid for better dampining. i use 4 of the msr4's on all of maxx trucks. i can provide setup info if you need it.