Bob,
add or not. the lower cups will not fit over the shaft eyelets from the Traxxas part number. I wanted to test fit them. I am taking off the BB springs from my b4.1 and going to try to fit them on the B44.1

also A Pro local is running Red front springs and Gray rear springs on his b4.1
They said you need to cut down the eyelets .060" and it's best to use 2 limiters to keep stock travel. the springs are a little bigger I guess.

I am getting ready to order 3 sets of each spring in every color in the next few days..