I just bought a set of green Losi springs 2.5 for the front and Losi blue 2.5 springs for the rear on my 2WD Traxxas Slash, 2.5 blue shock in the rear will not fit! There is almost a whole inch of no spring. Do I use spacers? Or is it fine with 3-4 spacers. Also I filled all the shocks with new stock Traxxas shock oil and I filled each shock all the way up to the top of the thread. Is that bad or incorrect to fill it up to the tippy top? Thank you.