Join Date: Jan 2010
Location: West of the Mississippi
I run 4.10's on 245/75R15's, so I'd go at least 4.56's or 4.88's as recommended by others. Also, you are right. There are no 4.27 diffs for our rigs. Since I ran 4.56's on my 4.0L XJ with 32's, I'd go with 4.88's on 33's or higher. It is quite the thick ring gear and small pinion for the D30 though. I'm sure there are thousands of wranglers that have run that setup anyways.
2010 WK Laredo 5.7L, 2004 WJ 4.7L (totaled), 1959 CJ-5, 1996 XJ (sold), 1989 YJ Wrangler 4.2L (Sold)