Just to clarify....a 3.08 is a great R&P ratio for a .86 T5 transmission. That same R&P ratio is way too tall for a .72 S10 T5 transmission......and I've got an extra 3.08 differential as proof. I'm currently running a 3.42 diff which has me turning 2000 rpms at 70 mph. A 3.50-3.73 would give you higher efficiency at a lower ground speed. The 235 makes it's best torque between 1600-2400 and you'll maximize your vacuum reading at 2100-2400 rpms.
Dave
