View Full Version : 98 rear end

09-07-2012, 06:59 PM
whats the best rear end to run with my rb25. I want to get the rpms down onn the freeway. I've heard that the j30 diff is the one i want. I have my stock se diff and at 80 im up in the 4000 rpms range.

09-07-2012, 07:12 PM
stock is like a 4.01, j30 is like a 3.7, and a q45 diff is like 3.4 and will work on a s14 with some modification.

09-07-2012, 07:14 PM
with a j30 your rpms at 70 maybe will lower 250 rpms.