Those are the same ones I bought. See the piece in the open end of the cage in the item pic? Mine pops in and out and I was kinda guessing leaving it in would make more bottom end power than the open throat. Correct?

I just finished building a new revised kicker. Still could use a little more work, but I've been messing with it for 5 hours trying to get the right bends, angles, and length and it's close enough for the time being. 
7/8 of an inch shorter than stock lt500, somewhat copied the look of the Yoshi LTR kicker. Just used steel instead of alluminum. Try to get pics of that for ya'll in a few hours.

After the family leaves from gift swapping and chowin down I'll get back to setting the timing and checking for intake/exhaust leaks. Just bare with me, it's coming along.... slowly. I honestly think by this weekend, weather permitting, it'll get to hit some humps and jumps....... possibly the dump.