Anybody got a clue how much of a differance going from a 2.73 to a 3.42 would make my speedo be off?My speedo did read I was going 10 mph slower than I was going before the change.Dont know why.I topped out yesterday at 130 on my speedo but my trans won`t shift into o.d at wot.I dont think I was going that fast.Maybe close,it got there quick but quite pulling at 130 0r so.Not exactly sure of my rpm`s but my buddy in the passenger side said I was around 5 grand.I did the tech equations thing but it said at that rpm Id only be doingabout 111.I`m pretty sure I was going faster than that.

 

your estimates are correct.. about 110 at 5k..