X5 - final drive ratio question

[RamVA]

Hey all - I'm interested in picking up a early X5 with a manual transmission. I drove a vehicle I liked today, a 2001 with sport package, but was somewhat surprised by how short the gearing was. 1st and 2nd felt very bright, and in 5th gear at 75 the motor was turning 3500 RPM. This seems high for a truck and high for a BMW. I don't remember the automatic 3.0 version I drove a few years ago being so high strung.

Overall I think it made the truck more fun to drive, but I'm worried about the noise level on the highway and to some extent the fuel economy.

My question: Are there multiple rear-ends for these trucks, and if so how different are they? Is this a 5-speed thing, a sport package thing, a standalone option, or are they all like that?

Thanks in advance