LOL...
OK, the no-slip is made by richmond gear. it is similar in looks to the lockright, ez locker, aussie locker, quicklock... it like an evolved lockright containing more parts that make it work much quieter. aussie locker having tighter tolerances and such still doesn't make it compare to a no-slip.
they are all a lunch box locker meaning that they fit inside the carrier and replace the spider and side gears. they are limited in strength to the carrier itself and the crosspin.
stepping up means a full carrier replacement locker or LSD. the detroit no-spin by tractech, the truetrac LS by tractech, the ARB, OX, Eaton, Auburn units as well. but at a greater cost.
spline count is allways different but very specific. you currently have a 27 spline 8.25 and you want the extra strength of stepping up to 29 spline shafts. the 27 spline carrier will not fit the 29 spline shafts without machine work. so you either need to machine your 27 spline carrier to fit the 29 spline shafts or get a 29 spline carrier. which can be kinda pricey.
add that to the $350 tag that someone quoted on the no-slip and you come within full replacemt carrier locker range.