I have put 91 axles in a 86 rear with the SLP take-off posi. I am done with everything else, but the block that holds the c-clips in won't fit!!! (yes i pulled the axles out to lock them in)

What the hell is going on! Do i have to shave off some material at the end of the axle? Can i increase the depth of the notch in the block?! HELP!!!

OK, i figured it out, but i have one final question. The "block" that goes inbetween the axles... which way does it go? Does the tapered end go up or down, or does it matter?