differential gearing question please help!
i just recently bought my 97 ranger splash extended cab for 800 dollars. the reason so cheap is the previous owner put a different rear end in it out of a mazda b series 4x4, my truck is 2wd it doesnt make sense to me but any way when im on the highway the speedo is off by like 30 mph and the engine is running at a high rpm and im barely keepin up with traffic. what do i need to do to fix this? this is my first encounter with such a problem any help would be great. thanks