All true on the 4.27's, and I have a couple sets for sale if youre interested (PM me). As to the 4.30's, yes you can run them in a Waggy D44, mine are installed and ready to roll. The D44 4.30s are a Spicer only gear manufactured for Isuzu D44s, and are "thick", meaning you run them on the 3 series D44 carrier...