differences between '99 and 2k 3.0?

[rangertodd]

Hey everybody, I'm a ranger newbie looking for my first truck. I've been lurking the forums trying to gain as much insight as I can to make an informed purchase. Right now I'm looking at a '99 XLT 2wd 3.0 with a 5-speed. Looking at the engine ratings page got me puzzled. Why does the '99 3.0 rate at 145 horses and 178 ftlb of torque, but the 2k engine ups both figures to 150 and 190 respectively? What changes came in the 2000 and 2001 models, and can they be retrofitted into a '99 for that extra 7% torque?