I have a manual transmission from a 94 Ram V6 1500. Speedometer gear from my old automatic which was a 1992 518 from a 5.2L Van. My rear differential is an 8 3/4 from an early 70's D150. I ruined my 3.23's and replaced them with a set of 3.55's. Tires are 275 60 15 which is nowhere near any stock size of any Dodge truck. This bucket of parts is in my 87 Ram and I was just using my Father GPS (Global Positioning) to observe the error in actual speed vs observed speed. Dead on accurate. 100km/hr when the needle hides the little hash mark is 100km/hr. 120, same thing.
